From dc65e96a229ebdb32d8996567f36a14a3f51635c Mon Sep 17 00:00:00 2001
From: Michele Bigi <mikbigi@gmail.com>
Date: Sun, 20 Sep 2026 08:38:59 +0200
Subject: [PATCH] Apply the finding engine to schematic and PCB reviews.

FACT, REQUIREMENT, and INFERENCE are separate fields; datasheet provenance
lives in the rule DB so Recommended cannot stay ERROR; LLM output is REVIEW.
Designer decisions persist across rescans. Schematic and PCB share one library
and the same finding object in the report UI.
---
 backend/periscopex/finding_engine.py          | 288 ++++++++++++++++++
 backend/periscopex/models.py                  |  13 +
 backend/periscopex/pcb_checks.py              |   3 +-
 backend/periscopex/pcb_power_thermal.py       |   9 +
 backend/periscopex/pcb_review.py              |   5 +
 backend/periscopex/validate.py                |  17 +-
 backend/routers/reports.py                    |  48 ++-
 backend/services/pcb_pipeline.py              |   9 +-
 backend/services/validation.py                |   7 +
 docs/motore-finding.md                        | 114 +++++++
 docs/piano-pcb-review.md                      | 255 +++-------------
 frontend/content/changelog.md                 |   9 +
 .../src/components/report/finding-card.tsx    |  58 ++++
 frontend/src/lib/types.ts                     |  15 +
 tests/test_finding_engine.py                  | 135 ++++++++
 tests/test_finding_schema.py                  |  23 ++
 16 files changed, 797 insertions(+), 211 deletions(-)
 create mode 100644 backend/periscopex/finding_engine.py
 create mode 100644 docs/motore-finding.md
 create mode 100644 tests/test_finding_engine.py

diff --git a/backend/periscopex/finding_engine.py b/backend/periscopex/finding_engine.py
new file mode 100644
index 0000000..49350d5
--- /dev/null
+++ b/backend/periscopex/finding_engine.py
@@ -0,0 +1,288 @@
+"""Shared finding engine for schematic and PCB.
+
+FACT / REQUIREMENT / INFERENCE stay in separate fields. Datasheet
+provenance lives in the rule catalog, not in LLM prose. Recommended
+never becomes ERROR. LLM output is REVIEW, never RULE.
+"""
+
+from __future__ import annotations
+
+from datetime import datetime, timezone
+from typing import Any, Iterable, Literal
+
+from pydantic import BaseModel
+
+from backend.periscopex.models import Finding
+
+Provenance = Literal["MANDATORY", "RECOMMENDED", "TYPICAL", "EXAMPLE"]
+FindingClass = Literal["RULE", "RISK", "REVIEW", "INFO"]
+EvidenceStatus = Literal["SUFFICIENT", "INSUFFICIENT"]
+
+_LLM_SOURCES = frozenset({None, "review", "pcb_review"})
+_SOFT_PROVENANCE = frozenset({"RECOMMENDED", "TYPICAL", "EXAMPLE"})
+
+
+class RuleRecord(BaseModel):
+    """One row in the rule DB (not free-text from the model)."""
+    rule_id: str
+    provenance: Provenance
+    finding_class: FindingClass
+    domain: Literal["schema", "pcb", "shared"] = "shared"
+    source: str | None = None
+    requirement: str = ""
+
+
+class DesignerDecision(BaseModel):
+    """Stored intent so a rescan does not re-nag the same FACT."""
+    decision_id: str
+    fingerprint: str
+    rule_id: str | None = None
+    designator: str = ""
+    net: str | None = None
+    aspect: str | None = None
+    intent: str = ""
+    reason: str = ""
+    user_id: str = ""
+    created_at: str = ""
+
+
+# rule_id → catalog. Optional override: (rule_id, source).
+_RULES: dict[str, RuleRecord] = {}
+_RULES_BY_SOURCE: dict[tuple[str, str], RuleRecord] = {}
+
+
+def _add(rule_id: str, provenance: Provenance, cls: FindingClass, *,
+         domain: Literal["schema", "pcb", "shared"] = "shared",
+         source: str | None = None, requirement: str = "") -> None:
+    rec = RuleRecord(
+        rule_id=rule_id, provenance=provenance, finding_class=cls,
+        domain=domain, source=source, requirement=requirement,
+    )
+    _RULES[rule_id] = rec
+    if source:
+        _RULES_BY_SOURCE[(rule_id, source)] = rec
+
+
+def _seed() -> None:
+    if _RULES:
+        return
+    # Schematic
+    for rid, req in (
+        ("PE-MUX-001", "Pin function must match the mux / datasheet pin table."),
+        ("PE-NC-001", "NC pins must not be connected."),
+        ("PE-DEC-001", "Supply pin requires a decoupling capacitor on that net."),
+        ("PE-DEC-002", "Decoupling capacitor value vs datasheet."),
+        ("PE-I2C-001", "I2C bus requires pull-ups."),
+        ("PE-I2C-002", "I2C pull-up value vs datasheet."),
+        ("PE-RST-001", "Reset pin requires the specified pull."),
+        ("PE-RST-002", "Reset pull value vs datasheet."),
+        ("PE-BOM-001", "BOM MPN must match the netlist part."),
+        ("PE-BOM-002", "BOM line missing from the netlist."),
+        ("PE-DNP-001", "DNP / fitted state vs netlist."),
+        ("PE-DRT-001", "Operating voltage must not exceed the capacitor rating."),
+    ):
+        _add(rid, "MANDATORY", "RULE", domain="schema", requirement=req)
+    for rid in ("PE-TH-001", "PE-TH-003"):
+        _add(rid, "TYPICAL", "RISK", domain="schema",
+             requirement="Thermal estimate only with I_load and θJA from specs.")
+    _add("PE-PWR-001", "MANDATORY", "RISK", domain="shared",
+         source="power_margin_check",
+         requirement="I_load vs regulator capability (not Iout_max).")
+    _add("PE-PWR-001", "MANDATORY", "RULE", domain="pcb",
+         source="pcb_power_thermal",
+         requirement="Trace width × copper thickness vs I_load (IPC-2221 when ΔT known).")
+    for rid, prov, cls, req in (
+        ("PE-SEQ-001", "RECOMMENDED", "RISK", "Power sequencing from datasheet notes."),
+        ("PE-FLT-001", "RECOMMENDED", "RISK", "Filter topology vs datasheet."),
+        ("PE-FLT-002", "RECOMMENDED", "RISK", "Filter component vs datasheet."),
+        ("PE-FLT-003", "RECOMMENDED", "RISK", "Filter cutoff vs datasheet."),
+        ("PE-XTAL-001", "MANDATORY", "RULE", "Crystal load capacitance vs Cl."),
+        ("PE-XTAL-002", "RECOMMENDED", "RISK", "Crystal layout / load-cap note."),
+        ("PE-XTAL-003", "RECOMMENDED", "RISK", "Crystal drive / Cl note."),
+        ("PE-LF-001", "TYPICAL", "INFO", "Lifecycle / NRND."),
+        ("PE-LF-002", "TYPICAL", "INFO", "Lifecycle / last-time-buy."),
+        ("PE-LF-003", "TYPICAL", "INFO", "Lifecycle / obsolete."),
+        ("PE-INT-001", "TYPICAL", "REVIEW", "Internal feature (ESD/pull-up) vs net."),
+        ("PE-ESR-001", "RECOMMENDED", "RISK", "HF / ESR coverage."),
+        ("PE-ERRATA-001", "MANDATORY", "REVIEW", "Published errata."),
+    ):
+        _add(rid, prov, cls, domain="schema", requirement=req)
+    # PCB geometry
+    _add("PE-LAY-001", "MANDATORY", "RULE", domain="pcb",
+         requirement="PCB pad net must match the schematic pin net.")
+    _add("PE-LAY-002", "MANDATORY", "RULE", domain="pcb",
+         requirement="Schematic ref must have a footprint (except #PWR).")
+    _add("PE-LAY-003", "TYPICAL", "INFO", domain="pcb",
+         requirement="KiCad /net vs flattened schematic net is the same net.")
+    for rid, req in (
+        ("PE-PLC-001", "Decoupling proximity max_distance_mm from layout_rules."),
+        ("PE-PLC-002", "Thermal via min_via_count from layout_rules."),
+        ("PE-PLC-003", "same_layer decoupling from layout_rules."),
+        ("PE-PLC-004", "Keepout from layout_rules."),
+        ("PE-SI-001", "Differential skew vs length_match mm."),
+    ):
+        _add(rid, "MANDATORY", "RULE", domain="pcb", requirement=req)
+    _add("PE-VIA-001", "TYPICAL", "INFO", domain="pcb",
+         requirement="Via current share from I_load and via count (no invented table).")
+    _add("PE-THM-001", "RECOMMENDED", "RISK", domain="pcb",
+         requirement="Dissipation vs courtyard pour/vias when P is known.")
+    _add("PE-KEL-001", "RECOMMENDED", "RISK", domain="pcb",
+         requirement="Kelvin/sense pin should not share the load net.")
+    _add("PE-STCH-001", "TYPICAL", "INFO", domain="pcb",
+         requirement="GND stitch via in the bbox of a signal over a GND pour.")
+
+
+_seed()
+
+
+def lookup_rule(rule_id: str | None, source: str | None = None) -> RuleRecord | None:
+    if not rule_id:
+        return None
+    if source and (rule_id, source) in _RULES_BY_SOURCE:
+        return _RULES_BY_SOURCE[(rule_id, source)]
+    return _RULES.get(rule_id)
+
+
+def finding_fingerprint(f: Finding) -> str:
+    return "|".join([
+        f.rule_id or f.source or "",
+        f.designator or "",
+        f.net or "",
+        f.aspect or "",
+    ])
+
+
+def complete_finding(f: Finding) -> Finding:
+    """Fill FACT/REQUIREMENT/INFERENCE, clamp provenance and evidence."""
+    rec = lookup_rule(f.rule_id, f.source)
+    if not (f.facts or "").strip():
+        f.facts = f.finding
+    if not (f.requirement or "").strip():
+        f.requirement = (rec.requirement if rec and rec.requirement else None) or f.why
+    if not (f.action or "").strip():
+        f.action = f.recommendation or ""
+    if not (f.recommendation or "").strip() and f.action:
+        f.recommendation = f.action
+
+    llm = (f.source in {None, "review", "pcb_review"}) and not f.rule_id
+
+    if rec:
+        if not f.provenance:
+            f.provenance = rec.provenance
+        if not f.finding_class:
+            f.finding_class = rec.finding_class
+    elif llm or f.source in {"review", "pcb_review"}:
+        f.finding_class = f.finding_class or "REVIEW"
+    elif f.source:
+        f.finding_class = f.finding_class or "RULE"
+    else:
+        f.finding_class = f.finding_class or "REVIEW"
+
+    if f.source in {"review", "pcb_review"}:
+        f.finding_class = "REVIEW"
+
+    quote = (f.source_quote or "").strip()
+    if f.evidence_status == "INSUFFICIENT":
+        pass
+    elif llm and not quote:
+        f.evidence_status = "INSUFFICIENT"
+    elif not (f.facts or "").strip() or not (f.requirement or "").strip():
+        f.evidence_status = "INSUFFICIENT"
+    else:
+        f.evidence_status = f.evidence_status or "SUFFICIENT"
+
+    if f.evidence_status == "INSUFFICIENT":
+        if f.status == "ERROR":
+            f.status = "WARNING" if quote or rec else "INFO"
+        if f.finding_class == "RULE":
+            f.finding_class = "INFO"
+        if not (f.inference or "").strip():
+            f.inference = (
+                "Insufficient evidence — not inventing a violation or default "
+                "(no 1 oz / 10 °C / 50 Ω / IEC)."
+            )
+
+    prov = f.provenance or (rec.provenance if rec else None)
+    if prov in _SOFT_PROVENANCE and f.status == "ERROR":
+        f.status = "WARNING"
+        if f.finding_class == "RULE":
+            f.finding_class = "RISK"
+
+    if f.finding_class == "RULE" and f.confidence is None:
+        f.confidence = 0.9 if f.evidence_status == "SUFFICIENT" else 0.3
+    elif f.finding_class == "REVIEW" and f.confidence is None:
+        f.confidence = 0.55 if quote else 0.35
+    elif f.confidence is None:
+        f.confidence = 0.5 if f.evidence_status == "SUFFICIENT" else 0.25
+
+    if not (f.why or "").strip():
+        f.why = f.requirement
+    if not (f.finding or "").strip():
+        f.finding = f.facts
+    return f
+
+
+def complete_findings(findings: list[Finding]) -> None:
+    for f in findings:
+        complete_finding(f)
+
+
+def apply_decisions(
+    findings: list[Finding],
+    decisions: Iterable[DesignerDecision] | Iterable[dict[str, Any]],
+) -> None:
+    """Rescan must not re-nag a stored designer decision as ERROR."""
+    by_fp: dict[str, DesignerDecision] = {}
+    for raw in decisions:
+        d = raw if isinstance(raw, DesignerDecision) else DesignerDecision.model_validate(raw)
+        by_fp[d.fingerprint] = d
+    if not by_fp:
+        return
+    for f in findings:
+        fp = finding_fingerprint(f)
+        d = by_fp.get(fp)
+        if not d:
+            continue
+        f.suppressed = True
+        f.decision_id = d.decision_id
+        f.status = "INFO"
+        f.finding_class = "INFO"
+        extra = f"Designer decision {d.decision_id}: {d.intent}"
+        if d.reason:
+            extra = f"{extra} — {d.reason}"
+        if extra not in (f.inference or ""):
+            f.inference = ((f.inference or "") + " " + extra).strip()
+        if not (f.action or "").strip():
+            f.action = "Keep the stored intent; no layout/schematic change required."
+            f.recommendation = f.action
+
+
+def decision_from_review(
+    finding: Finding,
+    *,
+    state: str,
+    reason: str,
+    user_id: str,
+) -> DesignerDecision | None:
+    if state not in {"wontfix", "false_positive"}:
+        return None
+    ts = datetime.now(timezone.utc).strftime("%Y%m%d%H%M%S")
+    fp = finding_fingerprint(finding)
+    return DesignerDecision(
+        decision_id=f"DEC-{finding.designator}-{ts}",
+        fingerprint=fp,
+        rule_id=finding.rule_id,
+        designator=finding.designator,
+        net=finding.net,
+        aspect=finding.aspect,
+        intent=state,
+        reason=reason,
+        user_id=user_id,
+        created_at=datetime.now(timezone.utc).isoformat(),
+    )
+
+
+def upsert_decision(store: list[dict[str, Any]], decision: DesignerDecision) -> list[dict[str, Any]]:
+    out = [row for row in store if row.get("fingerprint") != decision.fingerprint]
+    out.append(decision.model_dump())
+    return out
diff --git a/backend/periscopex/models.py b/backend/periscopex/models.py
index 065248a..a49de15 100644
--- a/backend/periscopex/models.py
+++ b/backend/periscopex/models.py
@@ -356,6 +356,19 @@ class Finding(BaseModel):
     cad_sheet: str | None = None     # schematic sheet filename for plugin sync
     cad_uuid: str | None = None      # KiCad symbol/pin uuid
     variant: str | None = None      # DNP / ECO / assembly variant
+    # Finding engine (docs/motore-finding.md) — optional for legacy JSON.
+    facts: str = ""
+    requirement: str = ""
+    inference: str = ""
+    provenance: Literal["MANDATORY", "RECOMMENDED", "TYPICAL", "EXAMPLE"] | None = None
+    finding_class: Literal["RULE", "RISK", "REVIEW", "INFO"] | None = None
+    confidence: float | None = None
+    evidence_status: Literal["SUFFICIENT", "INSUFFICIENT"] | None = None
+    calculation: str = ""
+    assumptions: list[str] = []
+    action: str = ""
+    decision_id: str | None = None
+    suppressed: bool = False
 
 
 class ValidationReport(BaseModel):
diff --git a/backend/periscopex/pcb_checks.py b/backend/periscopex/pcb_checks.py
index 9fe4c76..52b737a 100644
--- a/backend/periscopex/pcb_checks.py
+++ b/backend/periscopex/pcb_checks.py
@@ -5,7 +5,7 @@ from __future__ import annotations
 import logging
 from collections import Counter
 
-from backend.periscopex.derating import build_derating_table
+from backend.periscopex.finding_engine import complete_findings
 from backend.periscopex.models import DesignGraph, Finding, LayoutGraph
 from backend.periscopex.pcb_net_match import check_pcb_net_match
 from backend.periscopex.pcb_power_thermal import (
@@ -31,6 +31,7 @@ def assign_pcb_finding_ids(findings: list[Finding]) -> None:
         f.finding_id = f"PCB-{f.designator}-{counter[f.designator]:03d}"
         if not (f.recommendation or "").strip():
             f.recommendation = _FALLBACK_FIX
+    complete_findings(findings)
 
 
 def check_pcb_derating(graph: DesignGraph) -> list[Finding]:
diff --git a/backend/periscopex/pcb_power_thermal.py b/backend/periscopex/pcb_power_thermal.py
index 7f59aac..ac086cf 100644
--- a/backend/periscopex/pcb_power_thermal.py
+++ b/backend/periscopex/pcb_power_thermal.py
@@ -141,6 +141,9 @@ def check_pcb_power_traces(
                 ),
                 source="pcb_power_thermal",
                 rule_id="PE-PWR-001",
+                evidence_status="INSUFFICIENT",
+                calculation="",
+                assumptions=["IPC-2221 not applied without copper thickness."],
                 net=net,
                 pins=[],
             ))
@@ -162,6 +165,8 @@ def check_pcb_power_traces(
                 recommendation="Add Tjmax to the shared library extraction, then re-run PCB review.",
                 source="pcb_power_thermal",
                 rule_id="PE-PWR-001",
+                evidence_status="INSUFFICIENT",
+                assumptions=["ΔT is Tjmax − 25 °C from the datasheet, never a default 10 °C."],
                 net=net,
                 pins=[],
             ))
@@ -189,6 +194,10 @@ def check_pcb_power_traces(
             ),
             source="pcb_power_thermal",
             rule_id="PE-PWR-001",
+            calculation=(
+                f"I = k·ΔT^0.44·A^0.725 → {i_allow:.3g} A; I_load={i_load:.3g} A"
+            ),
+            evidence_status="SUFFICIENT",
             net=net,
             pins=[],
         ))
diff --git a/backend/periscopex/pcb_review.py b/backend/periscopex/pcb_review.py
index 50d1cf7..3c14b31 100644
--- a/backend/periscopex/pcb_review.py
+++ b/backend/periscopex/pcb_review.py
@@ -30,6 +30,11 @@ are in the context. Never assume 1 oz or 50 Ω.
 - Creepage/clearance only if the extraction or IEC number is in context.
 
 ### Findings
+This is a **design review** of geometry vs the library JSON, not a second \
+datasheet exam. Put board measurements in `finding` (FACT), library text in \
+`why` (REQUIREMENT). Recommended layout notes are never ERROR. Missing \
+width/thickness/I_load → say insufficient evidence, do not assume 1 oz.
+
 Every finding MUST have status ERROR, WARNING, or INFO and a non-empty \
 recommendation. Call submit_review. Empty findings with checked_areas is \
 valid when the layout matches the extraction.
diff --git a/backend/periscopex/validate.py b/backend/periscopex/validate.py
index de72978..022c064 100644
--- a/backend/periscopex/validate.py
+++ b/backend/periscopex/validate.py
@@ -20,6 +20,7 @@ from dotenv import load_dotenv
 
 load_dotenv()
 
+from backend.periscopex.finding_engine import complete_findings
 from backend.periscopex.models import (
     ComponentConstraints,
     ComponentType,
@@ -149,6 +150,12 @@ neighbor's datasheet that you fetched via `get_datasheet_excerpt` — this \
 links the page number to the right datasheet.
 - **recommendation**: What to change (for ERROR/WARNING only).
 
+This is a **design review**, not a design rule. Put observations in \
+`finding` (FACT), datasheet text in `why` (REQUIREMENT), and judgment \
+only there — do not invent millimetres, IEC numbers, or typical values. \
+Recommended datasheet notes are never ERROR. If evidence is missing, say \
+so (Unverified) instead of guessing.
+
 ### Calibration
 ERROR only for clear violations: required pin floating, voltage exceeding \
 absolute max, required external component completely missing, wrong \
@@ -922,12 +929,19 @@ def _parse_review(
                 mpn=mpn,
                 source_designator=src_designator,
                 finding=item["finding"],
+                facts=str(item.get("finding") or ""),
+                requirement=why,
+                inference=str(item.get("inference") or ""),
                 why=why,
                 status=status,
                 source_page=page,
                 source_quote=item.get("source_quote", ""),
                 recommendation=item.get("recommendation", ""),
+                action=str(item.get("recommendation") or ""),
                 reference=f"{src_mpn} datasheet p.{page if page is not None else '?'}",
+                source="review",
+                finding_class="REVIEW",
+                evidence_status="SUFFICIENT" if quote else "INSUFFICIENT",
             ))
         except (KeyError, TypeError, ValueError) as exc:
             print(f"Skipping malformed finding for {ic_ref}: {exc}", file=sys.stderr)
@@ -937,11 +951,12 @@ def _parse_review(
 
 
 def assign_finding_ids(findings: list[Finding]) -> None:
-    """Assign finding_id: {designator}-{001}, {002}, ..."""
+    """Assign finding_id: {designator}-{001}, {002}, ... then run the finding engine."""
     counter: Counter[str] = Counter()
     for f in findings:
         counter[f.designator] += 1
         f.finding_id = f"{f.designator}-{counter[f.designator]:03d}"
+    complete_findings(findings)
 
 
 # ---------------------------------------------------------------------------
diff --git a/backend/routers/reports.py b/backend/routers/reports.py
index d49bef0..53c8621 100644
--- a/backend/routers/reports.py
+++ b/backend/routers/reports.py
@@ -11,6 +11,12 @@ from fastapi import APIRouter, HTTPException, Request
 from fastapi.responses import JSONResponse, Response
 from pydantic import BaseModel
 
+from backend.periscopex.finding_engine import (
+    apply_decisions,
+    complete_findings,
+    decision_from_review,
+    upsert_decision,
+)
 from backend.periscopex.models import Finding
 from backend.periscopex.review_workflow import (
     ReviewError,
@@ -49,6 +55,20 @@ async def get_report(project_id: str, request: Request):
     merged = merge_schema_pcb_reports(schema, pcb)
     if merged is None:
         raise HTTPException(404, "Report not found — run the pipeline first")
+    findings = _findings_from_report(merged)
+    complete_findings(findings)
+    dec_key = f"{prefix}/decisions.json"
+    if storage.exists(dec_key):
+        try:
+            apply_decisions(findings, storage.read_json(dec_key) or [])
+        except Exception:
+            pass
+    merged["findings"] = [json.loads(f.model_dump_json()) for f in findings]
+    summary = {"ERROR": 0, "WARNING": 0, "INFO": 0, "total": len(findings)}
+    for f in findings:
+        if f.status in summary:
+            summary[f.status] += 1
+    merged["summary"] = summary
     return JSONResponse(merged)
 
 
@@ -148,7 +168,17 @@ async def put_finding_review(project_id: str, finding_id: str, body: ReviewBody,
     owner_user_id, _ = await resolve_or_404(request, project_id)
     user_id = get_user_id(request)
     key, report_data = _load_report(storage, owner_user_id, project_id)
-    ids = {f.finding_id for f in _findings_from_report(report_data) if f.finding_id}
+    prefix = proj_svc.project_prefix(owner_user_id, project_id)
+    findings = _findings_from_report(report_data)
+    ids = {f.finding_id for f in findings if f.finding_id}
+    if finding_id not in ids:
+        pcb_key = f"{prefix}/pcb_report.json"
+        if storage.exists(pcb_key):
+            pcb_data = storage.read_json(pcb_key)
+            pcb_findings = _findings_from_report(pcb_data)
+            if finding_id in {f.finding_id for f in pcb_findings if f.finding_id}:
+                key, report_data, findings = pcb_key, pcb_data, pcb_findings
+                ids = {f.finding_id for f in findings if f.finding_id}
     if finding_id not in ids:
         raise HTTPException(404, "Finding not found")
     try:
@@ -164,6 +194,22 @@ async def put_finding_review(project_id: str, finding_id: str, body: ReviewBody,
         raise HTTPException(400, str(exc)) from exc
     report_data["review_states"] = states
     storage.write_json(key, report_data)
+    if body.state in {"wontfix", "false_positive"}:
+        found = next(
+            (f for f in _findings_from_report(report_data) if f.finding_id == finding_id),
+            None,
+        )
+        if found is not None:
+            dec = decision_from_review(
+                found, state=body.state, reason=body.reason, user_id=user_id,
+            )
+            if dec is not None:
+                prefix = proj_svc.project_prefix(owner_user_id, project_id)
+                dkey = f"{prefix}/decisions.json"
+                existing = storage.read_json(dkey) if storage.exists(dkey) else []
+                if not isinstance(existing, list):
+                    existing = []
+                storage.write_json(dkey, upsert_decision(existing, dec))
     return JSONResponse(states.get(finding_id) or {"state": "open", "reason": ""})
 
 
diff --git a/backend/services/pcb_pipeline.py b/backend/services/pcb_pipeline.py
index 0d73fa0..9ebd92e 100644
--- a/backend/services/pcb_pipeline.py
+++ b/backend/services/pcb_pipeline.py
@@ -7,6 +7,7 @@ untouched. Does not write ``.kicad_pcb`` or packing coordinates.
 
 from __future__ import annotations
 
+import json
 import logging
 from datetime import datetime, timezone
 from pathlib import Path
@@ -17,7 +18,7 @@ from backend.periscopex.cad_bridge import (
     cad_index_from_graph,
     write_cad_bridge,
 )
-from backend.periscopex.functional_groups import build_placement_plan
+from backend.periscopex.finding_engine import apply_decisions
 from backend.periscopex.graph import build_graph
 from backend.periscopex.models import ComponentConstraints, DesignGraph, LayoutGraph, ValidationReport
 from backend.periscopex.pcb_checks import assign_pcb_finding_ids, run_pcb_checks
@@ -227,6 +228,12 @@ async def run_pcb_pipeline(
             _step(project_id, "write_report", "running")
             assign_pcb_finding_ids(findings)
             annotate_findings_cad(findings, cad_index_from_graph(graph))
+            dec_path = ws.local_path("decisions.json")
+            if dec_path.is_file():
+                try:
+                    apply_decisions(findings, json.loads(dec_path.read_text()))
+                except Exception:
+                    logger.exception("decisions.json apply failed")
             summary: dict[str, int] = {"ERROR": 0, "WARNING": 0, "INFO": 0}
             for f in findings:
                 summary[f.status] = summary.get(f.status, 0) + 1
diff --git a/backend/services/validation.py b/backend/services/validation.py
index 8279d7f..fe4b138 100644
--- a/backend/services/validation.py
+++ b/backend/services/validation.py
@@ -21,6 +21,7 @@ from typing import Awaitable, Callable
 
 log = logging.getLogger(__name__)
 
+from backend.periscopex.finding_engine import apply_decisions
 from backend.periscopex.models import (
     ComponentConstraints,
     ComponentType,
@@ -789,6 +790,12 @@ async def validate_design_async(
     def _write_report(paused: bool = False) -> ValidationReport:
         annotate_findings_cad(all_findings, graph.cad_index)
         assign_finding_ids(all_findings)
+        dec_path = existing_path.with_name("decisions.json")
+        if dec_path.is_file():
+            try:
+                apply_decisions(all_findings, json.loads(dec_path.read_text()))
+            except Exception:
+                log.exception("decisions.json apply failed")
         summary = {"total": len(all_findings), "ERROR": 0, "WARNING": 0, "INFO": 0}
         for f in all_findings:
             summary[f.status] = summary.get(f.status, 0) + 1
diff --git a/docs/motore-finding.md b/docs/motore-finding.md
new file mode 100644
index 0000000..f531a06
--- /dev/null
+++ b/docs/motore-finding.md
@@ -0,0 +1,114 @@
+# Motore finding — schema e PCB (stesso oggetto)
+
+Fonte: specifica di Michele (Project chat). Vale per **analizzatore schematico e PCB**. Un finding è un oggetto riproducibile, non un paragrafo LLM.
+
+Libreria datasheet: **una** (`library/extracted` + extracted/ di progetto). L’esame PDF profondo gira **una volta** (pipeline schema). Il job PCB consuma quella cache e aggiunge solo geometria.
+
+---
+
+## 1. Tre strati — non mescolare
+
+Ogni finding ha **tre campi distinti**:
+
+| Strato | Nome campo | Chi lo produce | Cosa può contenere |
+| --- | --- | --- | --- |
+| **FACT** | `facts` | Motore deterministico (netlist, BOM, `.kicad_pcb`) | Solo osservabili: pin, net, mm, V, A, width, thickness |
+| **REQUIREMENT** | `requirement` | Rule DB + estrazione libreria (citazione, pagina, MPN) | Testo **sourced**. Provenance nel DB, non nella prosa del modello |
+| **INFERENCE** | `inference` | Ingegnere / LLM **solo** qui | Giudizio. Mai copiare un’inferenza in `facts` o `requirement` |
+
+Non mescolare: un check non scrive “probabilmente sottodimensionato” dentro `facts`. Se manca un parametro, `evidence_status=INSUFFICIENT` e si **dice** che manca — non si inventa 1 oz, 10 °C, 50 Ω, IEC.
+
+`finding` / `why` restano per compatibilità UI (copia di facts / requirement).
+
+---
+
+## 2. Provenance datasheet (rule DB)
+
+Sul **record di regola**, non nel testo LLM:
+
+| `provenance` | Significato | Classe / severity |
+| --- | --- | --- |
+| **MANDATORY** | Shall / abs-max / pin NC | Può essere **RULE** + ERROR |
+| **RECOMMENDED** | Should / layout note | **Mai ERROR**. RISK o INFO |
+| **TYPICAL** | Typical / default application | INFO o RISK, mai RULE ERROR |
+| **EXAMPLE** | Figure / typical application circuit | REVIEW o INFO |
+
+**Recommended ≠ ERROR.** Il clamp è nel motore (`complete_finding`).
+
+---
+
+## 3. Classi — Design Rule ≠ Design Review
+
+| `finding_class` | Ruolo |
+| --- | --- | --- |
+| **RULE** | Violazione di un requisito MANDATORY misurato (FACT vs REQUIREMENT). Deterministico. |
+| **RISK** | Margine / derating / inferenza ingegneristica con evidenza parziale. |
+| **REVIEW** | Esame AI (schema o PCB). Non è una design rule. |
+| **INFO** | Inventario, evidenza insufficiente, decisione del progettista, skip onesto. |
+
+LLM `source=review` / `pcb_review` → sempre **REVIEW**, mai RULE.
+
+---
+
+## 4. Intent + memoria DECISION
+
+Il progettista può dichiarare un intent (es. **PSEL tied low on purpose**). Persistenza: `decisions.json` nel progetto, fingerprint:
+
+`{rule_id\|source}|{designator}|{net}|{aspect}`
+
+`wontfix` / `false_positive` sul report **scrive** una DECISION. Al rescan il motore **non ri-naga** come ERROR: finding `suppressed=true`, `finding_class=INFO`, `decision_id` valorizzato.
+
+---
+
+## 5. Severity, confidence, evidence — indipendenti
+
+- `status` (severity): ERROR | WARNING | INFO
+- `confidence`: 0–1 (quanto è solido il FACT+REQUIREMENT)
+- `evidence_status`: SUFFICIENT | INSUFFICIENT
+
+Alto confidence + INFO è legale (misura chiara, non è un fault). Bassa confidence + ERROR **non** è legale se evidence è INSUFFICIENT: si declassa.
+
+---
+
+## 6. Oggetto finding (riproducibile)
+
+Campi obbligatori del motore (oltre a designator / MPN / ids esistenti):
+
+```
+facts, requirement, inference
+source (pagina/MPN/rule_id)
+calculation
+assumptions[]
+confidence
+status (severity)
+action          # cosa fare; UI usa anche recommendation
+provenance
+finding_class
+evidence_status
+decision_id? suppressed?
+```
+
+---
+
+## 7. Libreria unica / esame unico
+
+| Store | Path |
+| --- | --- |
+| Estrazioni IC | `library/extracted/{safe_mpn}.json` (shared) ∪ `extracted/` progetto |
+| PDF blob | `library/datasheets/blobs/{md5}.pdf` |
+
+PCB: `review_ic_async(..., pdf_path=None)` se c’è pintable. Skip: `no library extraction — run schematic review first`.
+
+---
+
+## 8. Cosa è solo PCB
+
+Geometria board: width/thickness, via, pour courtyard, placement mm, return/stitch, pad-net vs schema (`PE-LAY-*` gerarchia `/net`). **Non** duplicare check schema (mux, LED, filtri netlist).
+
+---
+
+## 9. Fasi (non fingere completezza)
+
+**Fase A (questa slice):** oggetto finding + clamp provenance/class + decisions + UI schema/PCB + libreria condivisa + check geometria già gated.
+
+**Fase B (pianificata):** gerarchia component→system; timing; energy/thermal solo con θJA/P/I_load; ratings; derating PASS/MARGIN/RISK; PI; SI oltre skew mm; return path oltre stitch INFO; ESD/EMI; thermal FEM; BOM↔PCB↔datasheet; SPOF come REVIEW.
diff --git a/docs/piano-pcb-review.md b/docs/piano-pcb-review.md
index bf70639..5adb155 100644
--- a/docs/piano-pcb-review.md
+++ b/docs/piano-pcb-review.md
@@ -1,238 +1,79 @@
-# Piano — PCB review (esame AI + check deterministici)
+# Piano — PCB review (esame geometria + stesso motore finding)
 
-Fonte di verità per **Periscope Layout review**. Non è un auto-placer.
+Specifica finding: [`motore-finding.md`](motore-finding.md). Schema e PCB usano **lo stesso oggetto**. Questo file è il job layout.
 
-**Delta vs revisione precedente:** l’esame del board è **agentico come la pipeline schema** (datasheet + neighborhood + tool, findings ERROR/WARNING/INFO con **sempre** una `recommendation`). Restano i check numerici gated. Auto-placement / pack / write-back pcbnew restano **fuori**.
+**Non** è un auto-placer. PCB-only = geometria (mm, width, copper, via, pour, return stitch, pad-net). Validazione netlist / mux / LED resta schema.
 
-Prodotto: esaminare un `.kicad_pcb` già (parzialmente) sbrogliato — placement, routing, impedenze, lunghezze, decoupling, filtri, derating, compliance datasheet — e dire *cosa è sbagliato e come sistemarlo*. Non si spostano footprint e non si scrive rame.
+Contratto:
 
-Contratto rispetto a [`docs/piano-implementazione.md`](piano-implementazione.md):
-
-| | Schema (già in produzione) | PCB review (questo piano) | Placement F2 pack (fuori) |
+| | Schema | PCB review | Placement F2 (fuori) |
 | --- | --- | --- | --- |
-| Promessa | Lo schema rispetta il datasheet | Il **layout esistente** rispetta datasheet + geometria | Proporre xy nuovi |
-| Metodo | Check deterministici + **review LLM per-IC** | Stesso spirito: check + **review LLM per-IC sul PCB** | Skeleton `placement_pack.json` |
-| Trigger | BOM + netlist / `.kicad_sch` | + `.kicad_pcb` | PCB + `layout_rules` numerici |
-| Output | Finding pin/net, derating, review | Finding mm / net / Z0 / skew / via EP / layout AI; `PE-PLC*` `PE-SI*` `PE-LAY*` `PE-Z0*` | Proposte xy |
-| Job | `MODE=run` (`status`) | `MODE=pcb` (`pcb_status`) | `MODE=placement` (`placement_status`) |
+| Promessa | Netlist vs libreria datasheet | Layout vs libreria + geometria | xy nuovi |
+| Motore finding | FACT / REQUIREMENT / INFERENCE | uguale | — |
+| Deep exam PDF | **Una volta** → `library/extracted` | Consuma cache, `pdf_path=None` | — |
+| Job | `MODE=run` | `MODE=pcb` | `MODE=placement` |
+| Output | `report.json` | `pcb_report.json` (merge in GET /report) | pack json |
 
-Senza `.kicad_pcb` il progetto resta uno schema completo. Il report schema **non** si riempie di finding layout.
+Senza `.kicad_pcb` il progetto è schema-completo. Il report schema non si riempie di PE-PLC/PE-SI.
 
 ---
 
-## 0. Postura: esame AI, non progettazione
+## Motore (schema + PCB)
 
-Stesso spirito della Direct Datasheet Review: il modello legge datasheet + contesto del circuito **e** geometria del footprint/net, usa tool sul grafo, sottomette finding. Non progetta il board.
+Vedi `motore-finding.md`. Invarianti:
 
-### Domains e functional Groups
+1. Non mescolare FACT / REQUIREMENT / INFERENCE.
+2. Provenance **MANDATORY | RECOMMENDED | TYPICAL | EXAMPLE** nel rule DB. **Recommended ≠ ERROR**.
+3. Classi **RULE | RISK | REVIEW | INFO**. LLM = REVIEW, mai RULE.
+4. `decisions.json` + fingerprint: rescan non ri-naga (PSEL low intenzionale, ecc.).
+5. `status`, `confidence`, `evidence_status` indipendenti.
+6. Evidenza insufficiente → lo si dice, niente 1 oz / 10 °C / 50 Ω / IEC inventati.
+7. Oggetto riproducibile: facts, requirement, source, calculation, assumptions, confidence, severity, action.
 
-Obbligatori come contesto dell’esame (non come packing):
+UI report (schema e layout): stessa `FindingCard` — Fact / Requirement / Inference, badge classe e provenance.
 
-- **Domains** = isole sulle power net (`functional_groups.py` / `placement_plan.json`).
-- **Groups** = IC + satelliti con `role_hint` (`decoupling`, `bulk`, `filter`, `crystal`, …).
-
-Il job PCB **classifica** (riusa `build_placement_plan`) e passa domains/groups al reviewer e all’inventory. Non propone coordinate.
-
-La pipeline Placement (`POST …/placement/start`) resta topologia routing-first. F2 pack/export **parcheggiati**.
-
-### Placement = verifica (deterministico + AI)
-
-Misura ciò che è **già** sul board: distanza pad-cap, layer, via EP, keepout, crystal load caps. `placement_check` (`PE-PLC-001`…`004`) è il nucleo numerico. L’AI copre note di layout del datasheet **senza mm strutturato** (citazione + `Unverified:` se la quote non verifica), sempre con recommendation.
-
-### Routing = la stessa postura
-
-Lunghezze, coppie, bus, Z0, pad-net vs schema. `si_check` (`PE-SI-001`) solo con `length_match` mm. L’AI può flaggare crossing/loop evidenti **solo** se il contesto geometria lo mostra; niente 3W/IEC inventati.
-
-### Findings (come parte 1 / schema)
-
-Ogni finding PCB:
-
-- `status`: **ERROR** | **WARNING** | **INFO**
-- `recommendation` **obbligatoria** anche per INFO (cosa fare: spostare, allungare/accorciare, cambiare rating, verificare stackup, …)
-- `rule_id` sui check automatici; review AI: `source=pcb_review`
-- IDs `PCB-{designator}-{001}` per non collidere con lo schema
-
-Normalization resta **downgrade-only**.
+Libreria: `library/extracted/{safe_mpn}.json` ∪ extracted/ progetto. PDF in `library/datasheets/blobs/`.
 
 ---
 
-## 1. Job parallelo (riuso stack)
+## Job PCB (invariato nello stack)
 
 ```
-                    ┌─ MODE=run        → status              → report.json (schema)
-  Project files  ───┼─ MODE=placement  → placement_status    → placement_plan.json
-                    └─ MODE=pcb        → pcb_status          → pcb_report.json
+                    ┌─ MODE=run        → status           → report.json
+  Project files  ───┼─ MODE=placement  → placement_status → placement_plan.json
+                    └─ MODE=pcb        → pcb_status       → pcb_report.json
 ```
 
-### Riuso
+Stages: `ensure_graph` → `parse_pcb` → `classify` → `inventory` → `checks` → `ai_review` (layout vs library, no PDF) → `write_report`.
 
-| Pezzo | Path | Ruolo PCB |
-| --- | --- | --- |
-| Workspace / SSE | `pipeline.py` | `PipelineWorkspace`, broker |
-| Dispatch | `job_runner.py`, `pipeline_worker.py` | `MODE=pcb` |
-| API | `routers/pipeline.py` | `pcb/start`, `cancel`, `events`, inventory |
-| Meta | `projects.py` | `pcb_status`, `pcb_state`, `pcb_execution_name`, `pcb_cancel_requested` |
-| Parser | `parsers_kicad_pcb.py` | `LayoutGraph` |
-| Groups | `functional_groups.py` | domains + groups |
-| Placement | `placement_check.py` | PE-PLC-* |
-| SI | `si_check.py` | PE-SI-001 |
-| Filtri | `filter_check.py` | contesto; proximity solo con mm |
-| Derating | `derating.py` | Vop vs Vrated se entrambi noti |
-| Impedenza | `impedance_traces.py` | inventory Z0; finding se target numerico |
-| Review LLM | `services/validation.py` + prompt PCB | per-IC, stesso loop tool/`submit_review` |
-| Cad bridge | `cad_bridge.py` | `target: pcb` |
-| UI | report `finding-card`, sidebar, `types.ts`, `api.ts` | tab Layout, merge findings |
+Mutex vs analisi e vs placement. SSE `pcb_*`. IDs `PCB-{ref}-{001}`. KiCad `/net` vs net schema: **PE-LAY-003** una volta, non per-pad (`kicad_nets_match`).
 
-### Contratto job
+### Check PCB (geometria) — gated
 
-- Non tocca `status` schema.
-- Soft-cancel `pcb_cancel_requested`.
-- Mutex vs analisi e vs placement (event log condiviso).
-- SSE `pcb_step_update` / `pcb_complete` / `pcb_error` / `pcb_cancelled`.
-- Locale: `local/pcb/{id}`.
-- Heal zombie come placement.
-- LLM: stesso provider DeepSeek della review schema; `ApiLogger` stage `pcb_review`; billing via `get_billing()` (NullBilling in OSS).
-- Senza API key in test: skip AI, check deterministici restano.
-
-### Stages
-
-1. `ensure_graph` — `design_graph.json` o graph_build.
-2. `parse_pcb` — `layout_graph.json` / `parse_kicad_pcb`. Fail → error.
-3. `classify` — domains + groups (`build_placement_plan`); scrive `functional_groups.json` se manca.
-4. `inventory` — tracce, bus, lunghezze, Z0 → `pcb_inventory.json`.
-5. `checks` — deterministici fail-soft (`run_pcb_checks`).
-6. `ai_review` — per-IC come schema, contesto layout + group/domain + inventory del vicinato.
-7. `write_report` — `pcb_report.json`, cad-bridge, IDs `PCB-*`.
-
----
-
-## 2. Ingressi
-
-| Ingresso | Obbligatorio v1 |
+| ID | Gate |
 | --- | --- |
-| `.kicad_pcb` (`has_pcb`) | Sì |
-| `design_graph.json` | Sì |
-| `extracted/` + `layout_rules` / pintable | Per check numerici e AI |
-| **Shared library** `library/extracted/{safe_mpn}.json` | **Unico** store schema+PCB. Deep exam PDF una volta (pipeline schema). |
-| PDF datasheet | Solo per estrazione / review **schema**. PCB **non** riattacca il PDF. |
-| Stackup nel PCB | Per Z0 e ampacity; skip se assente |
+| PE-LAY-001…003 | pad/ref/hierarchy nets |
+| PE-PLC-001…004 | `layout_rules` numerici |
+| PE-SI-001 | `length_match` mm |
+| PE-DRT-001 | Vop e Vrated |
+| PE-PWR-001 | I_load + width; IPC solo con thickness e Tjmax |
+| PE-VIA-001 | via count + I_load (INFO, no tabella inventata) |
+| PE-THM-001 | P=I_load×drop, courtyard senza pour/via |
+| PE-KEL-001 | sense/Kelvin pintable + ≥2 altri sul net |
+| PE-STCH-001 | pour GND + segnale senza via GND nel bbox |
+| Creepage | **skip** senza numero datasheet/IEC |
+| Crystal keepout | PE-PLC-004 se kind=keepout |
+
+AI PCB: skip IC senza pintable (`run schematic review first`).
 
 ---
 
-## 3. Check (deterministici) + AI
+## Fasi
 
-### 3.1 Inventario (non finding)
+**A — shipped (questa slice):** oggetto finding condiviso, clamp provenance/class, decisions, UI, libreria unica, geometria gated, net-slash.
 
-Net con rame: lunghezza, layer, width min/max, via, coppia, bus, Z0 se stackup. Domains/groups elencati.
+**B — pianificata (non finta):** gerarchia component→system; timing; energy/thermal solo con parametri; ratings; derating PASS/MARGIN/RISK; PI; SI oltre skew; return path oltre stitch INFO; ESD/EMI; thermal FEM; BOM↔PCB↔datasheet; SPOF come REVIEW.
 
-### 3.2 Deterministici
+**C — fuori:** auto-place, write-back pcbnew, unire i job, sshd/keys.
 
-| ID | Cosa | Gate |
-| --- | --- | --- |
-| `PE-LAY-001` | Pad net ≠ pin net schema | entrambi noti |
-| `PE-LAY-002` | Ref schema senza footprint (skip `#PWR`) | graph + PCB |
-| `PE-PLC-001`…`004` | decoupling / via / same_layer / keepout | `layout_rules` numerici |
-| `PE-SI-001` | skew coppia | `length_match` mm |
-| `PE-DRT-001` | Vop > Vrated sul cap (derating.py) | entrambe le tensioni |
-| `PE-Z0-001` | Z0 fuori target | target in regola o netclass; mai 50 Ω default |
-| `PE-PWR-001` | Larghezza × spessore rame vs I_load | I_load + width; IPC-2221 solo con `copper_thickness_mm` e Tjmax (ΔT=Tjmax−25 °C) |
-| `PE-VIA-001` | I_load / N via | geometria via + I_load; INFO (niente tabella via inventata) |
-| `PE-THM-001` | P=I_load×(Vin−Vout) senza pour/via courtyard | I_load, Vin/Vout, courtyard |
-| `PE-KEL-001` | Pin sense/Kelvin su net di carico | nome pintable + ≥2 altri sul net |
-| `PE-STCH-001` | Segnale sopra pour GND senza via GND nel bbox | zone GND + segmenti; INFO |
-| Creepage | — | **skip** senza numero datasheet/IEC |
-| Crystal keepout | `PE-PLC-004` | `layout_rules` kind=keepout |
-
-Filtri: `check_filters` **non** duplicato nel report PCB (resta schema). L’AI e i groups usano `role_hint=filter` per proximity se c’è mm.
-
-### 3.3 AI exam (layout-only, shared library)
-
-Per ogni IC con **pintable in `library/extracted` o extracted/ di progetto** (stesso JSON):
-
-- **Non** si ri-legge il PDF. L’esame datasheet profondo è quello della pipeline schema.
-- System prompt **PCB**: layout vs JSON di libreria.
-- User: `format_library_extraction` + `build_pcb_layout_context`.
-- `review_ic_async(..., pdf_path=None)` — niente attach, niente quote-verify PDF.
-- Skip: `no library extraction — run schematic review first`.
-- Recommendation obbligatoria; isolation per-IC.
-
-UI: sezione report **PCB exam** (`pcb-exam-section.tsx`) — findings `source=pcb_review` e PE-PWR/THM/VIA/KEL/STCH. Nascosta con `?domain=schema`.
-
-### 3.4 Skip (no folklore)
-
-3W, creepage IEC senza numero, CPWG, HV isolation, length-match USB spec, confronto foto TI vs gerber, 1 oz / 10 °C / 50 Ω di default.
-
----
-
-## 4. UI
-
-| Superficie | Comportamento |
-| --- | --- |
-| Hub | **Run PCB review** se `hasPcb` |
-| `/project/[id]/pcb` | Stepper SSE (include `ai_review`) |
-| Sidebar | **Layout** → `/pcb` |
-| Report | Merge + sezione **PCB exam**; `?domain=layout`; badge Layout; recommendation sempre visibile |
-| Inventory | Traces/buses/Z0 + domains/groups |
-
----
-
-## 5. Fasi di implementazione
-
-Dopo **ogni** fase: test delle funzioni toccate, commit, push. Dopo ogni macro-fase operativa: deploy `ssh periscope` + `scripts/update-periscope.sh` (niente chiavi/sshd).
-
-### Fase 0 — Split schema / layout
-
-Togliere `placement_check` / `si_check` da `_run_deterministic_checks` schema. Eval schema: `layout=None` resta no-op.
-
-**Done when:** schema senza PCB = zero `PE-PLC`/`PE-SI`.
-
-### Fase 1 — Job + deterministici + UI (macro operativa)
-
-Meta `pcb_*`, worker, router, `run_pcb_checks`, inventory, report merge, UI start/progress/filtro.
-
-**Done when:** upload PCB → start → finding nel report. Deploy.
-
-### Fase 2 — AI exam + domains/groups (macro operativa)
-
-`classify` + `ai_review` per-IC, prompt PCB, recommendation obbligatoria, changelog Layout.
-
-**Done when:** con API key, IC con libreria producono finding `source=pcb_review` o coverage vuota; senza key, skip loggato. Deploy.
-
-### Fase 3 — Plugin + eval PCB
-
-Cad-bridge pcbnew; golden fixture. Packing resta fuori.
-
-### Fase 4 — Libreria unica + sezione PCB exam (macro operativa)
-
-Un store `library/extracted` (più extracted/ di progetto). PCB non duplica l’esame PDF. Sezione report PCB exam + PE-PWR/THM/VIA/KEL/STCH.
-
-**Done when:** IC senza pintable skipped; con libreria, AI layout-only; check IPC solo con stackup+Tjmax. Deploy.
-
----
-
-## 6. Fuori scope
-
-- Auto-placement, packing mm, write-back pcbnew.
-- Autore di sbroglio / change width.
-- SPICE / IBIS / EM.
-- Inventare mm, Ω, V/mm.
-- EasyEDA, Gerber come ingresso, PADS layout.
-- Unire il job PCB nella run schema.
-- Toccare ssh keys / `sshd`.
-
----
-
-## 7. Done (fixture)
-
-1. Decoupling 15 mm vs regola 2 mm → `PE-PLC-001` + recommendation.
-2. 1 mm → niente proximity.
-3. Skew coppia > `length_match` → `PE-SI-001`.
-4. Pad net mismatch → `PE-LAY-001`.
-5. Senza PCB → 400 sul start.
-6. AI: contesto contiene domain/group; finding senza recommendation rifiutati/completati dal parser.
-
----
-
-## 8. Relazione
-
-Wave G di `piano-implementazione.md` = questo job di **esame** (ora anche LLM). F2 pack non entra.
+Deploy: `ssh periscope` + `/root/periscope/scripts/update-periscope.sh`.
diff --git a/frontend/content/changelog.md b/frontend/content/changelog.md
index 8804ea0..b885ff6 100644
--- a/frontend/content/changelog.md
+++ b/frontend/content/changelog.md
@@ -2,6 +2,15 @@
 
 What's new in Periscope.
 
+## 2.32.0 — 2026-09-20 — Finding engine (schema + PCB)
+
+Same finding object on schematic analysis and PCB exam: FACT / REQUIREMENT / INFERENCE, datasheet provenance in the rule DB, RULE vs REVIEW, designer decisions, independent severity/confidence/evidence.
+
+- [New] `docs/motore-finding.md` — engine spec. `finding_engine.py` + `decisions.json`.
+- [New] Report cards show Fact / Requirement / Inference, class, provenance, insufficient evidence.
+- [Changed] Recommended datasheet notes cannot stay ERROR. LLM findings are REVIEW, never RULE.
+- [Changed] Schematic and PCB share `library/extracted`; PCB does not re-read the PDF.
+
 ## 2.31.0 — 2026-09-20 — Shared library PCB exam (no second PDF pass)
 
 Schematic and PCB share `library/extracted`. PCB AI consumes that cache (pintable required; no PDF attach). Report **PCB exam** section plus power-trace/thermal checks.
diff --git a/frontend/src/components/report/finding-card.tsx b/frontend/src/components/report/finding-card.tsx
index 30f0c73..c1b3492 100644
--- a/frontend/src/components/report/finding-card.tsx
+++ b/frontend/src/components/report/finding-card.tsx
@@ -60,6 +60,10 @@ export function FindingCard({
   const hasCommentSupport = !!(projectId && collaborators && onCommentAdded && onCommentDeleted);
   const expandable =
     !!finding.recommendation ||
+    !!finding.facts ||
+    !!finding.requirement ||
+    !!finding.inference ||
+    !!finding.calculation ||
     (hasCommentSupport && !!finding.finding_id) ||
     !!(projectId && finding.finding_id && onReviewSaved);
 
@@ -187,10 +191,64 @@ export function FindingCard({
                 {finding.rule_id}
               </span>
             )}
+            {finding.finding_class && (
+              <span className="inline-flex items-center rounded border border-border px-1.5 py-0.5 text-[10px] font-medium text-muted-foreground">
+                {finding.finding_class}
+              </span>
+            )}
+            {finding.provenance && (
+              <span className="inline-flex items-center rounded border border-border px-1.5 py-0.5 text-[10px] font-medium text-muted-foreground">
+                {finding.provenance}
+              </span>
+            )}
+            {finding.evidence_status === "INSUFFICIENT" && (
+              <span className="inline-flex items-center rounded border border-amber-500/30 bg-amber-500/10 px-1.5 py-0.5 text-[10px] font-medium text-amber-800 dark:text-amber-300">
+                Insufficient evidence
+              </span>
+            )}
+            {finding.suppressed && (
+              <span className="inline-flex items-center rounded border border-border px-1.5 py-0.5 text-[10px] font-medium text-muted-foreground">
+                Decision
+              </span>
+            )}
           </div>
 
           {open && (
             <div onClick={(e) => e.stopPropagation()}>
+              {(finding.facts || finding.requirement || finding.inference) && (
+                <dl className="mt-2 space-y-1.5 text-xs text-muted-foreground">
+                  {finding.facts ? (
+                    <div>
+                      <dt className="font-medium text-foreground">Fact</dt>
+                      <dd>{finding.facts}</dd>
+                    </div>
+                  ) : null}
+                  {finding.requirement ? (
+                    <div>
+                      <dt className="font-medium text-foreground">Requirement</dt>
+                      <dd>{finding.requirement}</dd>
+                    </div>
+                  ) : null}
+                  {finding.inference ? (
+                    <div>
+                      <dt className="font-medium text-foreground">Inference</dt>
+                      <dd>{finding.inference}</dd>
+                    </div>
+                  ) : null}
+                  {finding.calculation ? (
+                    <div>
+                      <dt className="font-medium text-foreground">Calculation</dt>
+                      <dd className="font-mono">{finding.calculation}</dd>
+                    </div>
+                  ) : null}
+                  {typeof finding.confidence === "number" ? (
+                    <div>
+                      <dt className="font-medium text-foreground">Confidence</dt>
+                      <dd>{Math.round(finding.confidence * 100)}%</dd>
+                    </div>
+                  ) : null}
+                </dl>
+              )}
               {finding.recommendation && (
                 <p className="text-sm text-muted-foreground mt-2 pl-1 border-l-2 border-muted leading-relaxed">
                   {finding.recommendation}
diff --git a/frontend/src/lib/types.ts b/frontend/src/lib/types.ts
index 6cf4afd..73bcc34 100644
--- a/frontend/src/lib/types.ts
+++ b/frontend/src/lib/types.ts
@@ -1,4 +1,7 @@
 export type FindingStatus = "ERROR" | "WARNING" | "INFO";
+export type FindingClass = "RULE" | "RISK" | "REVIEW" | "INFO";
+export type DatasheetProvenance = "MANDATORY" | "RECOMMENDED" | "TYPICAL" | "EXAMPLE";
+export type EvidenceStatus = "SUFFICIENT" | "INSUFFICIENT";
 
 export interface Finding {
   finding_id: string | null;
@@ -20,6 +23,18 @@ export interface Finding {
   cad_sheet?: string | null;
   cad_uuid?: string | null;
   variant?: string | null;
+  facts?: string;
+  requirement?: string;
+  inference?: string;
+  provenance?: DatasheetProvenance | null;
+  finding_class?: FindingClass | null;
+  confidence?: number | null;
+  evidence_status?: EvidenceStatus | null;
+  calculation?: string;
+  assumptions?: string[];
+  action?: string;
+  decision_id?: string | null;
+  suppressed?: boolean;
 }
 
 export interface FindingComment {
diff --git a/tests/test_finding_engine.py b/tests/test_finding_engine.py
new file mode 100644
index 0000000..81f2c3e
--- /dev/null
+++ b/tests/test_finding_engine.py
@@ -0,0 +1,135 @@
+"""Finding engine — FACT/REQUIREMENT/INFERENCE, provenance clamp, decisions."""
+
+from __future__ import annotations
+
+from backend.periscopex.finding_engine import (
+    DesignerDecision,
+    apply_decisions,
+    complete_finding,
+    finding_fingerprint,
+    lookup_rule,
+)
+from backend.periscopex.models import Finding
+from backend.periscopex.validate import assign_finding_ids, _parse_review
+
+
+def test_recommended_never_error():
+    f = Finding(
+        designator="U1",
+        finding="layout note",
+        why="place close",
+        status="ERROR",
+        rule_id="PE-THM-001",
+        source="pcb_power_thermal",
+        evidence_status="SUFFICIENT",
+        facts="no pour",
+        requirement="datasheet layout page",
+    )
+    complete_finding(f)
+    assert f.provenance == "RECOMMENDED"
+    assert f.status != "ERROR"
+    assert f.finding_class != "RULE"
+
+
+def test_llm_review_is_never_rule():
+    result = _parse_review(
+        {
+            "findings": [{
+                "finding": "strap",
+                "why": "datasheet",
+                "status": "ERROR",
+                "source_page": 2,
+                "source_quote": "PSEL must be high for 3.3 V.",
+                "recommendation": "Tie PSEL high.",
+            }],
+            "checked_areas": [],
+        },
+        "U1",
+        "PART",
+    )
+    f = result.findings[0]
+    complete_finding(f)
+    assert f.finding_class == "REVIEW"
+    assert f.facts
+    assert f.requirement
+    assert f.status == "ERROR"
+
+
+def test_insufficient_evidence_does_not_stay_error():
+    f = Finding(
+        designator="U1",
+        finding="narrow trace",
+        why="",
+        status="ERROR",
+        source="pcb_power_thermal",
+        rule_id="PE-PWR-001",
+        evidence_status="INSUFFICIENT",
+    )
+    complete_finding(f)
+    assert f.status != "ERROR"
+    assert "Insufficient evidence" in f.inference
+    assert f.finding_class != "RULE" or f.evidence_status == "INSUFFICIENT"
+
+
+def test_decision_suppresses_rescan_nag():
+    f = Finding(
+        designator="U1",
+        finding="PSEL low",
+        why="must be high",
+        status="ERROR",
+        rule_id="PE-MUX-001",
+        source="pin_mux_check",
+        net="PSEL",
+        aspect="config",
+        facts="PSEL net is GND",
+        requirement="PSEL high for 3V3",
+    )
+    complete_finding(f)
+    assert f.status == "ERROR"
+    d = DesignerDecision(
+        decision_id="DEC-1",
+        fingerprint=finding_fingerprint(f),
+        rule_id="PE-MUX-001",
+        designator="U1",
+        net="PSEL",
+        aspect="config",
+        intent="wontfix",
+        reason="PSEL low intentional",
+    )
+    apply_decisions([f], [d])
+    assert f.suppressed is True
+    assert f.status == "INFO"
+    assert f.finding_class == "INFO"
+    assert "PSEL low intentional" in f.inference
+
+
+def test_schematic_assign_ids_fills_engine_fields():
+    f = Finding(
+        designator="U3",
+        finding="NC tied",
+        why="NC must float",
+        status="ERROR",
+        rule_id="PE-NC-001",
+        source="nc_pin_check",
+    )
+    assign_finding_ids([f])
+    assert f.finding_id == "U3-001"
+    assert f.facts == "NC tied"
+    assert f.requirement
+    assert f.provenance == "MANDATORY"
+    assert f.finding_class == "RULE"
+    assert f.confidence is not None
+
+
+def test_same_object_pcb_and_schema():
+    assert lookup_rule("PE-NC-001").domain == "schema"
+    assert lookup_rule("PE-LAY-001").domain == "pcb"
+    sch = Finding(designator="U1", finding="x", status="INFO", rule_id="PE-NC-001", source="nc_pin_check")
+    pcb = Finding(designator="U1", finding="y", status="INFO", rule_id="PE-LAY-001", source="pcb_net_match")
+    complete_finding(sch)
+    complete_finding(pcb)
+    for obj in (sch, pcb):
+        assert obj.facts
+        assert obj.finding_class
+        assert obj.provenance
+        assert obj.evidence_status
diff --git a/tests/test_finding_schema.py b/tests/test_finding_schema.py
index bf69e1e..3a98036 100644
--- a/tests/test_finding_schema.py
+++ b/tests/test_finding_schema.py
@@ -57,6 +57,29 @@ def test_new_fields_round_trip_json():
     assert again.variant == "DNP"
 
 
+def test_engine_fields_round_trip():
+    f = Finding(
+        designator="U1",
+        finding="x",
+        status="WARNING",
+        facts="net GND",
+        requirement="PSEL high",
+        inference="intentional?",
+        provenance="RECOMMENDED",
+        finding_class="RISK",
+        confidence=0.4,
+        evidence_status="SUFFICIENT",
+        calculation="n/a",
+        assumptions=["firmware unknown"],
+        action="leave PSEL low",
+    )
+    again = Finding.model_validate(json.loads(f.model_dump_json()))
+    assert again.facts == "net GND"
+    assert again.provenance == "RECOMMENDED"
+    assert again.finding_class == "RISK"
+    assert again.assumptions == ["firmware unknown"]
+
+
 def test_unknown_extra_keys_do_not_break_legacy_payloads():
     f = Finding.model_validate(
         {