Add MODE=pcb layout exam job with AI and deterministic checks.

Parallel pcb_status pipeline: parse board, classify domains/groups,
inventory traces, PE-LAY/PLC/SI/DRT checks, per-IC datasheet review.
Findings merge into the report UI. No auto-place or pcbnew write-back.

backend/periscopex/cad_bridge.py

@@ -8,7 +8,7 @@ from pathlib import Path
 from backend.periscopex.models import CadIndexEntry, DesignGraph, Finding, ValidationReport
 
 CAD_BRIDGE_VERSION = 1
-_PCB_RULE_PREFIXES = ("PE-PLC", "PE-SI", "PE-LAY", "PE-3W", "PE-CLR")
+_PCB_RULE_PREFIXES = ("PE-PLC", "PE-SI", "PE-LAY", "PE-3W", "PE-CLR", "PE-DRT", "PE-Z0")
 
 
 def annotate_findings_cad(

backend/periscopex/pcb_checks.py

@@ -0,0 +1,110 @@
+"""Deterministic PCB review checks (no LLM). Fail-soft at the caller."""
+
+from __future__ import annotations
+
+import logging
+from collections import Counter
+
+from backend.periscopex.derating import build_derating_table
+from backend.periscopex.models import DesignGraph, Finding, LayoutGraph
+from backend.periscopex.pcb_net_match import check_pcb_net_match
+from backend.periscopex.placement_check import check_placement
+from backend.periscopex.si_check import check_si
+
+log = logging.getLogger(__name__)
+
+_FALLBACK_FIX = "Confirm the layout against the datasheet and adjust the board."
+
+
+def assign_pcb_finding_ids(findings: list[Finding]) -> None:
+    """IDs ``PCB-{designator}-{001}`` so they never collide with schema review."""
+    counter: Counter[str] = Counter()
+    for f in findings:
+        counter[f.designator] += 1
+        f.finding_id = f"PCB-{f.designator}-{counter[f.designator]:03d}"
+        if not (f.recommendation or "").strip():
+            f.recommendation = _FALLBACK_FIX
+
+
+def check_pcb_derating(graph: DesignGraph) -> list[Finding]:
+    """ERROR only when both Vop and Vrated exist and Vop exceeds Vrated."""
+    out: list[Finding] = []
+    for row in build_derating_table(graph):
+        rated = row.get("rated_voltage_v")
+        op = row.get("operating_voltage_v")
+        if rated is None or op is None:
+            continue
+        if float(op) <= float(rated):
+            continue
+        ref = str(row.get("designator") or "")
+        out.append(Finding(
+            designator=ref,
+            mpn=str(row.get("mpn") or ""),
+            aspect="derating",
+            finding=(
+                f"{ref} operates at {op:g} V with a {rated:g} V rating."
+            ),
+            why="Capacitor voltage rating must exceed the rail (no invented derating %).",
+            status="ERROR",
+            recommendation=(
+                f"Replace {ref} with a capacitor rated above {op:g} V, "
+                "or lower the rail."
+            ),
+            source="pcb_derating",
+            rule_id="PE-DRT-001",
+            net=row.get("net_plus"),
+            pins=[],
+        ))
+    return out
+
+
+def merge_schema_pcb_reports(
+    schema: dict | None, pcb: dict | None,
+) -> dict | None:
+    """Combine schematic report.json with pcb_report.json for GET /report."""
+    if not schema and not pcb:
+        return None
+    if not pcb:
+        out = dict(schema or {})
+        out["findings"] = [
+            f for f in (out.get("findings") or [])
+            if not str(f.get("finding_id") or "").startswith("PCB-")
+        ]
+        return out
+    if not schema:
+        return dict(pcb)
+    findings = [
+        f for f in (schema.get("findings") or [])
+        if not str(f.get("finding_id") or "").startswith("PCB-")
+    ]
+    findings.extend(pcb.get("findings") or [])
+    out = dict(schema)
+    out["findings"] = findings
+    summary: dict[str, int] = {"ERROR": 0, "WARNING": 0, "INFO": 0}
+    for f in findings:
+        st = f.get("status")
+        if st in summary:
+            summary[st] = summary.get(st, 0) + 1
+    out["summary"] = summary
+    return out
+
+
+def run_pcb_checks(
+    graph: DesignGraph,
+    constraints_map: dict,
+    layout: LayoutGraph | None,
+) -> list[Finding]:
+    """Placement, SI, pad-net match, derating — skip individually on error."""
+    out: list[Finding] = []
+    for name, fn in (
+        ("pcb_net_match", lambda: check_pcb_net_match(graph, layout)),
+        ("placement_check", lambda: check_placement(graph, constraints_map, layout)),
+        ("si_check", lambda: check_si(graph, constraints_map, layout)),
+        ("pcb_derating", lambda: check_pcb_derating(graph)),
+    ):
+        try:
+            out.extend(fn())
+        except Exception:
+            log.exception("PCB check %s failed — skipping", name)
+    assign_pcb_finding_ids(out)
+    return out

backend/periscopex/pcb_inventory.py

@@ -0,0 +1,97 @@
+"""Trace / bus inventory from a LayoutGraph. Numbers only, no findings."""
+
+from __future__ import annotations
+
+import re
+from collections import defaultdict
+
+from pydantic import BaseModel
+
+from backend.periscopex.models import DesignGraph, LayoutGraph, NetType
+from backend.periscopex.si_check import net_length_mm, partner_net
+
+
+_BUS_RE = re.compile(r"^(.*?)(\d+)$")
+
+
+class PcbNetInventory(BaseModel):
+    name: str
+    length_mm: float = 0.0
+    via_count: int = 0
+    layers: list[str] = []
+    width_min_mm: float | None = None
+    width_max_mm: float | None = None
+    pair: str | None = None
+    bus: str | None = None
+    net_type: str | None = None
+    z0_ohm: float | None = None
+
+
+class PcbInventoryReport(BaseModel):
+    nets: list[PcbNetInventory] = []
+    domains: list[str] = []
+    group_count: int = 0
+
+
+def _bus_name(net: str) -> str | None:
+    m = _BUS_RE.match(net.split("/")[-1].replace(".", "_"))
+    if not m:
+        return None
+    prefix, digits = m.group(1), m.group(2)
+    if not prefix or len(digits) > 3:
+        return None
+    return prefix.rstrip("_") or None
+
+
+def build_pcb_inventory(
+    layout: LayoutGraph,
+    graph: DesignGraph | None = None,
+    *,
+    domain_ids: list[str] | None = None,
+    group_count: int = 0,
+    z0_by_net: dict[str, float] | None = None,
+) -> PcbInventoryReport:
+    names: set[str] = set()
+    layers: dict[str, set[str]] = defaultdict(set)
+    widths: dict[str, list[float]] = defaultdict(list)
+    vias: dict[str, int] = defaultdict(int)
+    for s in layout.segments:
+        if not s.net:
+            continue
+        names.add(s.net)
+        if s.layer:
+            layers[s.net].add(s.layer)
+        if s.width > 0:
+            widths[s.net].append(s.width)
+    for v in layout.vias:
+        if v.net:
+            names.add(v.net)
+            vias[v.net] += 1
+    z0_by_net = z0_by_net or {}
+    rows: list[PcbNetInventory] = []
+    for name in sorted(names):
+        w = widths.get(name) or []
+        sch = graph.nets.get(name) if graph else None
+        nt = sch.net_type.value if sch and isinstance(sch.net_type, NetType) else (
+            str(sch.net_type) if sch and sch.net_type else None
+        )
+        partner = partner_net(name)
+        if partner and partner not in names:
+            partner = None
+        rows.append(PcbNetInventory(
+            name=name,
+            length_mm=round(net_length_mm(layout, name), 3),
+            via_count=vias.get(name, 0),
+            layers=sorted(layers.get(name, ())),
+            width_min_mm=min(w) if w else None,
+            width_max_mm=max(w) if w else None,
+            pair=partner,
+            bus=_bus_name(name),
+            net_type=nt,
+            z0_ohm=z0_by_net.get(name),
+        ))
+    return PcbInventoryReport(
+        nets=rows,
+        domains=list(domain_ids or []),
+        group_count=group_count,
+    )

backend/periscopex/pcb_net_match.py

@@ -0,0 +1,86 @@
+"""Pad net on the PCB vs pin net on the schematic graph.
+
+Silent when either side has no name. Power-flag footprints (#PWR) skipped.
+"""
+
+from __future__ import annotations
+
+from backend.periscopex.models import DesignGraph, Finding, LayoutGraph
+
+
+def _ensure_recommendation(f: Finding) -> Finding:
+    if not (f.recommendation or "").strip():
+        f.recommendation = (
+            "Align the PCB pad net with the schematic pin, then re-run PCB review."
+        )
+    return f
+
+
+def check_pcb_net_match(
+    graph: DesignGraph,
+    layout: LayoutGraph | None,
+) -> list[Finding]:
+    if layout is None or not layout.footprints:
+        return []
+    findings: list[Finding] = []
+    sch_refs = {
+        ref for ref in graph.components
+        if not ref.startswith("#")
+    }
+    pcb_refs = {
+        ref for ref in layout.footprints
+        if not ref.startswith("#")
+    }
+
+    for ref in sorted(sch_refs - pcb_refs):
+        comp = graph.components[ref]
+        findings.append(_ensure_recommendation(Finding(
+            designator=ref,
+            mpn=comp.mpn or "",
+            aspect="pcb_match",
+            finding=f"{ref} is in the schematic but has no footprint on the PCB.",
+            why="Layout review cannot check a part that is not placed.",
+            status="WARNING",
+            recommendation=f"Place {ref} on the board or remove it from the schematic/BOM.",
+            source="pcb_net_match",
+            rule_id="PE-LAY-002",
+            pins=[],
+        )))
+
+    for ref, fp in sorted(layout.footprints.items()):
+        if ref.startswith("#"):
+            continue
+        comp = graph.components.get(ref)
+        if comp is None:
+            continue
+        for pad in fp.pads:
+            if not pad.net or not pad.number:
+                continue
+            sch_net = graph.pin_net(ref, pad.number)
+            if not sch_net:
+                continue
+            if sch_net == pad.net:
+                continue
+            findings.append(_ensure_recommendation(Finding(
+                designator=ref,
+                mpn=comp.mpn or "",
+                aspect="pcb_match",
+                finding=(
+                    f"{ref}.{pad.number} PCB net '{pad.net}' does not match "
+                    f"schematic net '{sch_net}'."
+                ),
+                why=(
+                    "Datasheet and SI checks follow schematic net names. "
+                    "A pad on the wrong net is a layout error, not a BOM typo."
+                ),
+                status="ERROR",
+                recommendation=(
+                    f"Reconnect pad {ref}.{pad.number} to '{sch_net}' "
+                    f"(or fix the schematic if the PCB is authoritative)."
+                ),
+                source="pcb_net_match",
+                rule_id="PE-LAY-001",
+                net=pad.net,
+                pins=[pad.number],
+            )))
+    return findings

backend/periscopex/pcb_review.py

@@ -0,0 +1,125 @@
+"""PCB datasheet review prompt and layout neighborhood context (no auto-place)."""
+
+from __future__ import annotations
+
+import math
+
+from backend.periscopex.functional_groups import FunctionalGroupsReport
+from backend.periscopex.models import DesignGraph, LayoutGraph
+from backend.periscopex.pcb_inventory import PcbInventoryReport
+from backend.periscopex.si_check import net_length_mm
+
+PCB_SYSTEM_PROMPT = """\
+You are an electrical engineer reviewing a PCB layout against the IC \
+datasheet. This is an EXAM of the existing board — do not propose a new \
+floorplan, do not invent millimetres, and do not write Gerbers.
+
+### Coverage checklist (layout)
+- Domains (power-rail islands) and functional groups (IC + satellites: \
+decoupling, bulk, filter, crystal, pullup).
+- Placement: decoupling and crystal load caps vs datasheet layout notes \
+and any numeric layout_rules (max_distance_mm, same_layer, thermal vias).
+- Routing: net lengths, differential-pair skew, obvious stubs; length \
+match only when the datasheet gives millimetres.
+- Impedance: comment on Z0 only when stackup + width numbers are in the \
+context. Never assume 50 Ω.
+- Derating: flag a capacitor only when both operating and rated voltages \
+are present and Vop exceeds Vrated.
+- Filters: topology already on the schematic — check whether filter parts \
+sit with the IC they serve when coordinates exist.
+- Datasheet layout pages (typical application / PCB layout) vs this \
+neighborhood.
+
+### Findings
+Every finding MUST have status ERROR, WARNING, or INFO and a non-empty \
+recommendation (what to change on the board). INFO still needs a next \
+step (e.g. "Measure Z0 after stackup is filled in").
+
+Call submit_review. Empty findings with checked_areas is valid when the \
+layout matches the datasheet.
+"""
+
+
+def build_pcb_layout_context(
+    ic_ref: str,
+    graph: DesignGraph,
+    layout: LayoutGraph | None,
+    plan: FunctionalGroupsReport | None,
+    inventory: PcbInventoryReport | None = None,
+) -> str:
+    """Plain-text block appended to the schematic neighborhood for PCB review."""
+    lines = ["### PCB layout context (existing board — do not move parts)"]
+    domain_id = None
+    group = None
+    if plan is not None:
+        for g in plan.groups:
+            if g.ref == ic_ref:
+                group = g
+                break
+        for d in plan.domains:
+            if ic_ref in d.ic_refs:
+                domain_id = d.domain_id
+                lines.append(
+                    f"Domain: {d.domain_id} (power nets: {', '.join(d.power_nets) or '—'})"
+                )
+                break
+        if group is None:
+            lines.append("Functional group: (this IC is not in a classified group)")
+        else:
+            lines.append(
+                f"Functional group: {group.ref} subtype={group.component_subtype or '—'} "
+                f"rank={group.rank}"
+            )
+            sats = group.satellites or []
+            if sats:
+                lines.append("Satellites:")
+                for s in sats:
+                    xy = ""
+                    if layout and s.ref in layout.footprints:
+                        fp = layout.footprints[s.ref]
+                        xy = f" @ ({fp.x:.2f},{fp.y:.2f}) {fp.layer}"
+                    lines.append(
+                        f"  {s.ref} role={s.role_hint} nets={','.join(s.nets or [])}{xy}"
+                    )
+            else:
+                lines.append("Satellites: none")
+    if layout and ic_ref in layout.footprints:
+        fp = layout.footprints[ic_ref]
+        lines.append(
+            f"Footprint {ic_ref}: ({fp.x:.2f},{fp.y:.2f}) layer={fp.layer} "
+            f"pads={len(fp.pads)}"
+        )
+        near: list[str] = []
+        for other, ofp in layout.footprints.items():
+            if other == ic_ref:
+                continue
+            dist = math.hypot(ofp.x - fp.x, ofp.y - fp.y)
+            if dist <= 15.0:
+                near.append(f"{other} {dist:.1f}mm {ofp.layer}")
+        if near:
+            lines.append("Within 15 mm: " + "; ".join(sorted(near)[:24]))
+        pin_nets = graph.components.get(ic_ref)
+        if pin_nets:
+            seen: set[str] = set()
+            lines.append("Connected net lengths (PCB copper):")
+            for net_name in pin_nets.pins.values():
+                if not net_name or net_name in seen:
+                    continue
+                seen.add(net_name)
+                mm = net_length_mm(layout, net_name)
+                lines.append(f"  {net_name}: {mm:.2f} mm")
+    elif layout is None:
+        lines.append("No LayoutGraph — skip millimetre claims.")
+    else:
+        lines.append(f"No footprint for {ic_ref} on the PCB.")
+    if inventory and inventory.nets:
+        sample = inventory.nets[:12]
+        lines.append("Inventory sample (name length_mm pair):")
+        for n in sample:
+            lines.append(
+                f"  {n.name}: {n.length_mm:.2f} mm pair={n.pair or '—'} "
+                f"Z0={n.z0_ohm if n.z0_ohm is not None else '—'}"
+            )
+    if domain_id:
+        lines.append(f"(domain_id={domain_id})")
+    return "\n".join(lines)

backend/pipeline_worker.py

@@ -104,8 +104,13 @@ async def _run() -> None:
     elif mode == "placement":
         from backend.services import placement_pipeline as placement_svc
         await placement_svc.run_placement_pipeline(storage, user_id, project_id)
+    elif mode == "pcb":
+        from backend.services import pcb_pipeline as pcb_svc
+        await pcb_svc.run_pcb_pipeline(storage, user_id, project_id)
     else:
-        raise SystemExit(f"unknown MODE={mode!r}; expected 'run', 'regen', or 'placement'")
+        raise SystemExit(
+            f"unknown MODE={mode!r}; expected 'run', 'regen', 'placement', or 'pcb'"
+        )
 
 
 def main() -> None:

backend/routers/pipeline.py

@@ -463,7 +463,7 @@ async def events(project_id: str, request: Request):
                     break
                 ev = msg["event"]
                 # Skip placement events in the shared log.
-                if ev.startswith("placement_"):
+                if ev.startswith("placement_") or ev.startswith("pcb_"):
                     continue
                 yield {
                     "event": ev,
@@ -527,6 +527,9 @@ async def status(project_id: str, request: Request):
         "placement_status": meta.placement_status,
         "placement_state": meta.placement_state,
         "placement_running": (meta.placement_status or "draft") in ("queued", "running"),
+        "pcb_status": meta.pcb_status,
+        "pcb_state": meta.pcb_state,
+        "pcb_running": (meta.pcb_status or "draft") in ("queued", "running"),
         "healed": healed is not None,
     }
 
@@ -548,6 +551,7 @@ _PLACEMENT_SSE_TERMINAL = frozenset({
 async def start_placement(project_id: str, request: Request):
     """Enqueue the Placement topology pipeline (free, no analysis status change)."""
     from backend.services.placement_pipeline import analysis_busy, placement_busy
+    from backend.services.pcb_pipeline import pcb_busy
 
     storage = get_storage(request)
     owner_user_id, meta = await resolve_or_404(request, project_id)
@@ -557,6 +561,8 @@ async def start_placement(project_id: str, request: Request):
         raise HTTPException(409, "Analysis pipeline is running; wait or cancel it first")
     if placement_busy(meta):
         raise HTTPException(409, "Placement pipeline already running or queued")
+    if pcb_busy(meta):
+        raise HTTPException(409, "PCB review is running; wait or cancel it first")
     if (meta.placement_status or "draft") not in _PLACEMENT_START_OK:
         raise HTTPException(
             409,
@@ -694,7 +700,7 @@ async def placement_events(project_id: str, request: Request):
                 if not (
                     ev.startswith("placement_")
                     or ev == "heartbeat"
-                ):
+                ) or ev.startswith("pcb_"):
                     continue
                 yield {
                     "event": ev,
@@ -734,6 +740,187 @@ async def placement_events(project_id: str, request: Request):
     )
 
 
+# ---------------------------------------------------------------------------
+# PCB review pipeline (parallel — exam, not auto-place)
+# ---------------------------------------------------------------------------
+
+
+_PCB_START_OK = frozenset({"draft", "complete", "error", "cancelled"})
+_PCB_SSE_TERMINAL = frozenset({
+    "pcb_complete",
+    "pcb_error",
+    "pcb_cancelled",
+})
+
+
+@router.post("/pipeline/{project_id}/pcb/start", status_code=202)
+async def start_pcb(project_id: str, request: Request):
+    from backend.services.pcb_pipeline import analysis_busy, pcb_busy, placement_busy
+
+    storage = get_storage(request)
+    owner_user_id, meta = await resolve_or_404(request, project_id)
+    if not meta.has_pcb:
+        raise HTTPException(400, "Upload a .kicad_pcb before starting PCB review")
+    if not meta.has_bom or not meta.has_netlist:
+        raise HTTPException(400, "Upload BOM and netlist before starting PCB review")
+    if analysis_busy(meta):
+        raise HTTPException(409, "Analysis pipeline is running; wait or cancel it first")
+    if placement_busy(meta):
+        raise HTTPException(409, "Placement pipeline is running; wait or cancel it first")
+    if pcb_busy(meta):
+        raise HTTPException(409, "PCB review already running or queued")
+    if (meta.pcb_status or "draft") not in _PCB_START_OK:
+        raise HTTPException(
+            409,
+            f"Cannot start PCB review from pcb_status={meta.pcb_status}",
+        )
+
+    proj_svc.update_project(
+        storage, owner_user_id, project_id,
+        pcb_status="queued",
+        pcb_cancel_requested=False,
+        pcb_state=None,
+        pcb_execution_name=None,
+    )
+    try:
+        event_bridge.GCSEventBroker(storage, owner_user_id).clear_history(project_id)
+    except Exception:
+        logger.exception("failed to clear events before PCB start for %s", project_id)
+
+    try:
+        execution_name = job_runner.enqueue_pcb_pipeline(
+            project_id, owner_user_id,
+        )
+    except Exception:
+        logger.exception("enqueue_pcb_pipeline failed for %s", project_id)
+        proj_svc.update_project(
+            storage, owner_user_id, project_id,
+            pcb_status="error",
+            pcb_state={"error": "Failed to enqueue PCB worker"},
+        )
+        raise HTTPException(503, "Failed to enqueue PCB worker; please retry")
+
+    proj_svc.update_project(
+        storage, owner_user_id, project_id,
+        pcb_execution_name=execution_name,
+    )
+    return {"status": "started", "project_id": project_id}
+
+
+@router.post("/pipeline/{project_id}/pcb/cancel")
+async def cancel_pcb(project_id: str, request: Request):
+    from backend.services.pcb_pipeline import pcb_busy
+
+    storage = get_storage(request)
+    owner_user_id, meta = await resolve_or_404(request, project_id)
+    if not pcb_busy(meta):
+        raise HTTPException(
+            409,
+            f"PCB review is not running (pcb_status={meta.pcb_status})",
+        )
+    proj_svc.update_project(
+        storage, owner_user_id, project_id,
+        pcb_cancel_requested=True,
+    )
+    return {"status": "cancel_requested", "project_id": project_id}
+
+
+@router.get("/pipeline/{project_id}/pcb/inventory")
+async def get_pcb_inventory(project_id: str, request: Request):
+    storage = get_storage(request)
+    owner_user_id, _ = await resolve_or_404(request, project_id)
+    key = f"{proj_svc.project_prefix(owner_user_id, project_id)}/pcb_inventory.json"
+    if not storage.exists(key):
+        raise HTTPException(404, "PCB inventory not found — run PCB review first")
+    return storage.read_json(key)
+
+
+@router.get("/pipeline/{project_id}/pcb/events")
+async def pcb_events(project_id: str, request: Request):
+    owner_user_id, meta = await resolve_or_404(request, project_id)
+    storage = get_storage(request)
+
+    async def event_generator():
+        execution_name = meta.pcb_execution_name
+        crash_detected: dict[str, str | None] = {"reason": None}
+
+        async def watch_status() -> None:
+            poll_interval = 2.0
+            saw_active = (meta.pcb_status or "draft") in ("queued", "running")
+            while True:
+                await asyncio.sleep(poll_interval)
+                try:
+                    cur = proj_svc.get_project(storage, owner_user_id, project_id)
+                except Exception:
+                    continue
+                if cur is None:
+                    continue
+                pst = cur.pcb_status or "draft"
+                if pst in ("queued", "running"):
+                    saw_active = True
+                elif saw_active and pst in ("complete", "error", "cancelled"):
+                    crash_detected["reason"] = f"pcb_status={pst} (terminal)"
+                    return
+                if execution_name:
+                    try:
+                        state = job_runner.get_execution_state(execution_name)
+                    except Exception:
+                        state = "unknown"
+                    if state in _EXEC_TERMINAL and (
+                        saw_active or pst in ("queued", "running")
+                    ):
+                        crash_detected["reason"] = f"execution state={state}"
+                        return
+
+        watcher = asyncio.create_task(watch_status())
+        try:
+            async for msg in event_bridge.tail_events(
+                storage, owner_user_id, project_id,
+                terminal_events=_PCB_SSE_TERMINAL,
+            ):
+                if crash_detected["reason"] is not None:
+                    break
+                ev = msg["event"]
+                if not (ev.startswith("pcb_") or ev == "heartbeat"):
+                    continue
+                yield {
+                    "event": ev,
+                    "data": json.dumps(msg.get("data", {})),
+                }
+                if ev in _PCB_SSE_TERMINAL:
+                    return
+
+            if crash_detected["reason"] is not None:
+                cur = proj_svc.get_project(storage, owner_user_id, project_id)
+                err = None
+                if cur and cur.pcb_state:
+                    err = cur.pcb_state.get("error")
+                yield {
+                    "event": "pcb_error",
+                    "data": json.dumps({
+                        "error": err or crash_detected["reason"]
+                        or "pcb worker terminated without a terminal event",
+                        "synthetic": True,
+                    }),
+                }
+        finally:
+            watcher.cancel()
+            try:
+                await watcher
+            except (asyncio.CancelledError, Exception):
+                pass
+
+    return EventSourceResponse(
+        event_generator(),
+        ping=15,
+        headers={
+            "Cache-Control": "no-cache, no-transform",
+            "X-Accel-Buffering": "no",
+            "Connection": "keep-alive",
+        },
+    )
+
+
 # ---------------------------------------------------------------------------
 # Helpers
 # ---------------------------------------------------------------------------

backend/routers/projects.py

@@ -148,6 +148,9 @@ async def get_project(project_id: str, request: Request):
     healed_pl = proj_svc.heal_if_placement_stuck(storage, owner_user_id, project_id)
     if healed_pl is not None:
         meta = healed_pl
+    healed_pcb = proj_svc.heal_if_pcb_stuck(storage, owner_user_id, project_id)
+    if healed_pcb is not None:
+        meta = healed_pcb
     return meta.model_dump()
 
 

backend/routers/reports.py

@@ -40,10 +40,16 @@ async def get_report(project_id: str, request: Request):
     storage = get_storage(request)
     owner_user_id, _ = await resolve_or_404(request, project_id)
     prefix = proj_svc.project_prefix(owner_user_id, project_id)
-    key = f"{prefix}/report.json"
-    if not storage.exists(key):
+    schema_key = f"{prefix}/report.json"
+    pcb_key = f"{prefix}/pcb_report.json"
+    schema = storage.read_json(schema_key) if storage.exists(schema_key) else None
+    pcb = storage.read_json(pcb_key) if storage.exists(pcb_key) else None
+    from backend.periscopex.pcb_checks import merge_schema_pcb_reports
+
+    merged = merge_schema_pcb_reports(schema, pcb)
+    if merged is None:
         raise HTTPException(404, "Report not found — run the pipeline first")
-    return JSONResponse(storage.read_json(key))
+    return JSONResponse(merged)
 
 
 @router.get("/report/{project_id}/cad-bridge")

backend/services/event_bridge.py

@@ -49,6 +49,9 @@ TERMINAL_EVENTS = frozenset({
     "placement_complete",
     "placement_error",
     "placement_cancelled",
+    "pcb_complete",
+    "pcb_error",
+    "pcb_cancelled",
 })
 
 

backend/services/job_runner.py

@@ -350,6 +350,9 @@ def get_execution_state(execution_name: str | None) -> ExecutionState:
     if execution_name.startswith("local/placement/"):
         project_id = execution_name.split("/", 2)[-1]
         return _local_state(f"placement:{project_id}")
+    if execution_name.startswith("local/pcb/"):
+        project_id = execution_name.split("/", 2)[-1]
+        return _local_state(f"pcb:{project_id}")
     return _cloud_run_state(execution_name)
 
 
@@ -369,6 +372,10 @@ def cancel_execution(execution_name: str | None) -> None:
         project_id = execution_name.split("/", 2)[-1]
         _local_cancel(f"placement:{project_id}")
         return
+    if execution_name.startswith("local/pcb/"):
+        project_id = execution_name.split("/", 2)[-1]
+        _local_cancel(f"pcb:{project_id}")
+        return
     _cloud_run_cancel(execution_name)
 
 
@@ -383,3 +390,16 @@ def enqueue_placement_pipeline(project_id: str, user_id: str) -> str:
         proc_key=f"placement:{project_id}",
         execution_name=f"local/placement/{project_id}",
     )
+
+
+def enqueue_pcb_pipeline(project_id: str, user_id: str) -> str:
+    """Dispatch the parallel PCB review pipeline (deterministic + AI exam)."""
+    if use_cloud_run_jobs():
+        return _enqueue_cloud_run_job(
+            project_id, user_id, resume=False, free=False, mode="pcb",
+        )
+    return _spawn_local_subprocess(
+        project_id, user_id, resume=False, free=False, mode="pcb",
+        proc_key=f"pcb:{project_id}",
+        execution_name=f"local/pcb/{project_id}",
+    )

backend/services/pcb_pipeline.py

@@ -0,0 +1,346 @@
+"""PCB review pipeline — parallel to analysis (exam, not auto-place).
+
+Stages: ensure_graph → parse_pcb → classify → inventory → checks →
+ai_review → write_report. Uses ``pcb_status`` so analysis ``status`` is
+untouched. Does not write ``.kicad_pcb`` or packing coordinates.
+"""
+
+from __future__ import annotations
+
+import logging
+from datetime import datetime, timezone
+from pathlib import Path
+
+from backend.periscopex.cad_bridge import (
+    annotate_findings_cad,
+    build_cad_bridge,
+    cad_index_from_graph,
+    write_cad_bridge,
+)
+from backend.periscopex.functional_groups import build_placement_plan
+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
+from backend.periscopex.pcb_inventory import build_pcb_inventory
+from backend.services import projects as proj_svc
+from backend.services.pipeline import PipelineWorkspace, broker
+from backend.services.storage import StorageBackend
+
+logger = logging.getLogger(__name__)
+
+_PCB_ACTIVE = frozenset({"queued", "running"})
+_ANALYSIS_BUSY = frozenset({
+    proj_svc.STATUS_QUEUED,
+    proj_svc.STATUS_RUNNING,
+})
+_PLACEMENT_ACTIVE = frozenset({"queued", "running"})
+
+
+def _load_constraints_map(extracted_dir: Path) -> dict[str, ComponentConstraints]:
+    result: dict[str, ComponentConstraints] = {}
+    if not extracted_dir.is_dir():
+        return result
+    for f in extracted_dir.glob("*.json"):
+        try:
+            c = ComponentConstraints.model_validate_json(
+                f.read_text(encoding="utf-8"),
+            )
+        except Exception:
+            logger.exception("skipping bad extraction %s", f)
+            continue
+        result[c.mpn] = c
+    return result
+
+
+def _publish(project_id: str, event: str, data: dict) -> None:
+    broker.publish(project_id, event, data)
+
+
+def _step(project_id: str, stage: str, status: str, detail: str = "") -> None:
+    payload: dict = {"stage": stage, "status": status}
+    if detail:
+        payload["detail"] = detail
+    _publish(project_id, "pcb_step_update", payload)
+
+
+async def run_pcb_pipeline(
+    storage: StorageBackend, user_id: str, project_id: str,
+) -> None:
+    meta = proj_svc.get_project(storage, user_id, project_id)
+    if not meta:
+        raise ValueError(f"Project {project_id} not found")
+    if (meta.pcb_status or "draft") not in _PCB_ACTIVE:
+        logger.warning(
+            "pcb worker booted with pcb_status=%s for %s; exiting",
+            meta.pcb_status, project_id,
+        )
+        return
+
+    proj_svc.update_project(
+        storage, user_id, project_id,
+        pcb_status="running",
+        pcb_cancel_requested=False,
+        pcb_state=None,
+    )
+
+    try:
+        async with PipelineWorkspace(storage, user_id, project_id) as ws:
+            if _cancelled(storage, user_id, project_id):
+                _finish_cancelled(storage, user_id, project_id)
+                return
+
+            graph = await _ensure_graph(ws, meta, project_id)
+            if _cancelled(storage, user_id, project_id):
+                _finish_cancelled(storage, user_id, project_id)
+                return
+
+            _step(project_id, "parse_pcb", "running")
+            layout = _load_layout(ws)
+            if layout is None:
+                raise FileNotFoundError(
+                    "Missing or unreadable uploads/pcb.kicad_pcb"
+                )
+            _step(
+                project_id, "parse_pcb", "complete",
+                f"{len(layout.footprints)} footprints, {len(layout.nets)} nets",
+            )
+
+            if _cancelled(storage, user_id, project_id):
+                _finish_cancelled(storage, user_id, project_id)
+                return
+
+            _step(project_id, "classify", "running", "domains and groups")
+            cmap = _load_constraints_map(ws.local_path("extracted"))
+            plan = build_placement_plan(graph, cmap)
+            fg_path = ws.local_path("functional_groups.json")
+            fg_path.write_text(plan.model_dump_json(indent=2) + "\n")
+            ws._upload_file("functional_groups.json")
+            _step(
+                project_id, "classify", "complete",
+                f"{len(plan.domains)} domains, {len(plan.groups)} groups",
+            )
+
+            if _cancelled(storage, user_id, project_id):
+                _finish_cancelled(storage, user_id, project_id)
+                return
+
+            _step(project_id, "inventory", "running")
+            z0_by_net: dict[str, float] = {}
+            try:
+                from backend.periscopex.impedance_traces import analyze_where_needed
+
+                zrep = analyze_where_needed(layout, graph)
+                for row in zrep.get("nets") or []:
+                    if not isinstance(row, dict) or row.get("error"):
+                        continue
+                    name = str(row.get("net_name") or row.get("name") or "")
+                    z = row.get("z0_ohm") or row.get("mean_z0") or row.get("z0")
+                    if name and isinstance(z, (int, float)):
+                        z0_by_net[name] = float(z)
+            except Exception:
+                logger.exception("Z0 inventory skipped")
+            inventory = build_pcb_inventory(
+                layout, graph,
+                domain_ids=[d.domain_id for d in plan.domains],
+                group_count=len(plan.groups),
+                z0_by_net=z0_by_net,
+            )
+            inv_path = ws.local_path("pcb_inventory.json")
+            inv_path.write_text(inventory.model_dump_json(indent=2) + "\n")
+            ws._upload_file("pcb_inventory.json")
+            _step(
+                project_id, "inventory", "complete",
+                f"{len(inventory.nets)} routed nets",
+            )
+
+            if _cancelled(storage, user_id, project_id):
+                _finish_cancelled(storage, user_id, project_id)
+                return
+
+            _step(project_id, "checks", "running")
+            findings = run_pcb_checks(graph, cmap, layout)
+            _step(
+                project_id, "checks", "complete",
+                f"{len(findings)} deterministic findings",
+            )
+
+            if _cancelled(storage, user_id, project_id):
+                _finish_cancelled(storage, user_id, project_id)
+                return
+
+            _step(project_id, "ai_review", "running", "per-IC datasheet vs layout")
+            coverage: dict[str, list[str]] = {}
+            skipped: list[dict] = []
+            try:
+                from backend.services.api_logs import ApiLogger
+                from backend.services.pcb_validation import review_pcb_ics
+
+                pdf_dir = ws.local_path("uploads/datasheets")
+                pdf_dir.mkdir(parents=True, exist_ok=True)
+                logger_api = ApiLogger()
+
+                async def _prog(ref, turn, tool, detail):
+                    _step(
+                        project_id, "ai_review", "running",
+                        f"{ref} {tool} {detail}".strip(),
+                    )
+
+                ai_findings, coverage, skipped = await review_pcb_ics(
+                    graph, cmap, layout, plan, inventory,
+                    pdf_dir, storage=storage, api_logger=logger_api,
+                    on_progress=_prog,
+                )
+                findings.extend(ai_findings)
+                logger_api.flush(storage, user_id, project_id)
+                detail = (
+                    f"{len(ai_findings)} AI findings, {len(skipped)} skipped"
+                )
+            except Exception:
+                logger.exception("PCB AI review failed — keeping deterministic findings")
+                detail = "AI skipped (error)"
+            _step(project_id, "ai_review", "complete", detail)
+
+            if _cancelled(storage, user_id, project_id):
+                _finish_cancelled(storage, user_id, project_id)
+                return
+
+            _step(project_id, "write_report", "running")
+            assign_pcb_finding_ids(findings)
+            annotate_findings_cad(findings, cad_index_from_graph(graph))
+            summary: dict[str, int] = {"ERROR": 0, "WARNING": 0, "INFO": 0}
+            for f in findings:
+                summary[f.status] = summary.get(f.status, 0) + 1
+            report = ValidationReport(
+                project=project_id,
+                timestamp=datetime.now(timezone.utc).isoformat(),
+                findings=findings,
+                summary=summary,
+                coverage=coverage,
+                not_reviewed=skipped,
+            )
+            report_path = ws.local_path("pcb_report.json")
+            report_path.write_text(report.model_dump_json(indent=2) + "\n")
+            ws._upload_file("pcb_report.json")
+
+            bridge = build_cad_bridge(report, project_id)
+            write_cad_bridge(ws.local_path("periscope-findings.json"), bridge)
+            ws._upload_file("periscope-findings.json")
+            _step(project_id, "write_report", "complete", f"{len(findings)} findings")
+
+        proj_svc.update_project(
+            storage, user_id, project_id,
+            pcb_status="complete",
+            pcb_state={
+                "findings": len(findings),
+                "domains": len(plan.domains),
+                "groups": len(plan.groups),
+                "skipped": len(skipped),
+            },
+            pcb_cancel_requested=False,
+        )
+        _publish(project_id, "pcb_complete", {
+            "findings": len(findings),
+            "domains": len(plan.domains),
+            "groups": len(plan.groups),
+        })
+    except Exception as e:
+        logger.exception("pcb pipeline failed for %s", project_id)
+        proj_svc.update_project(
+            storage, user_id, project_id,
+            pcb_status="error",
+            pcb_state={"error": str(e)},
+        )
+        _publish(project_id, "pcb_error", {"error": str(e)})
+
+
+async def _ensure_graph(ws: PipelineWorkspace, meta, project_id: str) -> DesignGraph:
+    graph_path = ws.local_path("design_graph.json")
+    if graph_path.is_file():
+        _step(project_id, "ensure_graph", "running", "reusing design_graph.json")
+        graph = DesignGraph.model_validate_json(graph_path.read_text(encoding="utf-8"))
+        _step(
+            project_id, "ensure_graph", "complete",
+            f"{len(graph.components)} components (cached)",
+        )
+        return graph
+
+    _step(project_id, "ensure_graph", "running", "building design graph")
+    bom_path = ws.local_path("uploads/bom.csv")
+    netlist_path = ws.netlist_local_path()
+    if not bom_path.is_file() or not Path(netlist_path).is_file():
+        raise FileNotFoundError("Missing BOM or netlist for PCB graph_build")
+
+    col_map = meta.bom_columns or {}
+    graph = build_graph(
+        str(netlist_path),
+        str(bom_path),
+        str(ws.local_path("extracted")),
+        str(ws.local_path("patterns")),
+        str(ws.local_path("models")),
+        reference_col=col_map.get("reference", "Reference"),
+        mpn_col=col_map.get("mpn", "Manufacturer Part Number"),
+        include_subdesigns=(
+            set(meta.netlist_subdesigns)
+            if meta.netlist_subdesigns is not None
+            else None
+        ),
+        pcb_path=ws.local_path("uploads/pcb.kicad_pcb"),
+    )
+    graph_path.write_text(graph.model_dump_json(indent=2) + "\n")
+    ws._upload_file("design_graph.json")
+    _step(
+        project_id, "ensure_graph", "complete",
+        f"{len(graph.components)} components, {len(graph.nets)} nets",
+    )
+    return graph
+
+
+def _load_layout(ws: PipelineWorkspace) -> LayoutGraph | None:
+    cached = ws.local_path("layout_graph.json")
+    if cached.is_file():
+        try:
+            return LayoutGraph.model_validate_json(
+                cached.read_text(encoding="utf-8"),
+            )
+        except Exception:
+            logger.exception("bad layout_graph.json — trying pcb parse")
+
+    pcb = ws.local_path("uploads/pcb.kicad_pcb")
+    if not pcb.is_file():
+        return None
+    try:
+        from backend.periscopex.parsers_kicad_pcb import parse_kicad_pcb
+
+        layout = parse_kicad_pcb(pcb)
+        cached.write_text(layout.model_dump_json(indent=2) + "\n")
+        ws._upload_file("layout_graph.json")
+        return layout
+    except Exception:
+        logger.exception("kicad_pcb parse failed during PCB review")
+        return None
+
+
+def _cancelled(storage: StorageBackend, user_id: str, project_id: str) -> bool:
+    meta = proj_svc.get_project(storage, user_id, project_id)
+    return bool(meta and meta.pcb_cancel_requested)
+
+
+def _finish_cancelled(storage: StorageBackend, user_id: str, project_id: str) -> None:
+    proj_svc.update_project(
+        storage, user_id, project_id,
+        pcb_status="cancelled",
+        pcb_cancel_requested=False,
+    )
+    _publish(project_id, "pcb_cancelled", {})
+
+
+def pcb_busy(meta: proj_svc.ProjectMeta) -> bool:
+    return (meta.pcb_status or "draft") in _PCB_ACTIVE
+
+
+def analysis_busy(meta: proj_svc.ProjectMeta) -> bool:
+    return meta.status in _ANALYSIS_BUSY
+
+
+def placement_busy(meta: proj_svc.ProjectMeta) -> bool:
+    return (meta.placement_status or "draft") in _PLACEMENT_ACTIVE

backend/services/pcb_validation.py

@@ -0,0 +1,81 @@
+"""Per-IC PCB datasheet review — same agentic loop as schematic, layout context."""
+
+from __future__ import annotations
+
+import logging
+from pathlib import Path
+
+from backend.periscopex.cad_bridge import annotate_findings_cad, cad_index_from_graph
+from backend.periscopex.functional_groups import FunctionalGroupsReport
+from backend.periscopex.models import ComponentType, DesignGraph, Finding, LayoutGraph, ValidationReport
+from backend.periscopex.pcb_inventory import PcbInventoryReport
+from backend.periscopex.pcb_review import PCB_SYSTEM_PROMPT, build_pcb_layout_context
+from backend.periscopex.validate import ReviewResult
+from backend.services.api_logs import ApiLogger
+from backend.services.validation import _find_pdf, review_ic_async
+
+log = logging.getLogger(__name__)
+
+_FIX = "Adjust the layout to match the datasheet recommendation, then re-run PCB review."
+
+
+def _ensure_recs(findings: list[Finding]) -> None:
+    for f in findings:
+        if f.source in (None, "review"):
+            f.source = "pcb_review"
+        if not (f.recommendation or "").strip():
+            f.recommendation = _FIX
+
+
+async def review_pcb_ics(
+    graph: DesignGraph,
+    constraints_map: dict,
+    layout: LayoutGraph | None,
+    plan: FunctionalGroupsReport | None,
+    inventory: PcbInventoryReport | None,
+    pdf_dir: Path,
+    storage=None,
+    api_logger: ApiLogger | None = None,
+    on_progress=None,
+) -> tuple[list[Finding], dict[str, list[str]], list[dict]]:
+    """Review each IC with a datasheet. Fail-soft per IC. No auto-place."""
+    findings: list[Finding] = []
+    coverage: dict[str, list[str]] = {}
+    skipped: list[dict] = []
+    cache: dict = {}
+    for ref, comp in sorted(graph.components.items()):
+        if comp.component_type != ComponentType.IC:
+            continue
+        mpn = (comp.mpn or "").strip() or (comp.value or "").strip()
+        if not mpn:
+            skipped.append({"designator": ref, "reason": "no MPN in BOM"})
+            continue
+        pdf = _find_pdf(mpn, pdf_dir, storage=storage)
+        if pdf is None:
+            skipped.append({"designator": ref, "reason": "no datasheet PDF"})
+            continue
+        extra = build_pcb_layout_context(ref, graph, layout, plan, inventory)
+        try:
+            result, _trace = await review_ic_async(
+                graph, constraints_map, ref, str(pdf),
+                on_progress=on_progress,
+                api_logger=api_logger,
+                pdf_dir=pdf_dir,
+                storage=storage,
+                excerpt_cache=cache,
+                extra_context=extra,
+                system_prompt=PCB_SYSTEM_PROMPT,
+                log_stage="pcb_review",
+            )
+        except Exception:
+            log.exception("PCB AI review failed for %s — skipping", ref)
+            skipped.append({"designator": ref, "reason": "pcb_review error"})
+            continue
+        if not isinstance(result, ReviewResult):
+            continue
+        _ensure_recs(result.findings)
+        annotate_findings_cad(result.findings, cad_index_from_graph(graph))
+        findings.extend(result.findings)
+        if result.checked_areas:
+            coverage[ref] = list(result.checked_areas)
+    return findings, coverage, skipped

backend/services/pipeline.py

@@ -264,6 +264,8 @@ class PipelineWorkspace:
             self._upload_file("bom_summary.json")
             self._upload_file("derating.json")
             self._upload_file("report.json")
+            self._upload_file("pcb_report.json")
+            self._upload_file("pcb_inventory.json")
             self._upload_file("periscope-findings.json")
             self._upload_file("review_fingerprints.json")
             self._upload_file("api_logs.jsonl")

backend/services/projects.py

@@ -143,6 +143,12 @@ class ProjectMeta(BaseModel):
     placement_execution_name: str | None = None
     placement_cancel_requested: bool = False
 
+    # PCB review pipeline (parallel exam — does not overwrite analysis status).
+    pcb_status: str = "draft"
+    pcb_state: dict[str, Any] | None = None
+    pcb_execution_name: str | None = None
+    pcb_cancel_requested: bool = False
+
 
 def completed_review_refs_for_retry(
     storage: StorageBackend, user_id: str, project_id: str,
@@ -401,6 +407,70 @@ def heal_if_placement_stuck(
     )
 
 
+def heal_if_pcb_stuck(
+    storage: StorageBackend, user_id: str, project_id: str,
+) -> ProjectMeta | None:
+    """Unstick pcb_status queued/running when the worker is gone."""
+    meta = get_project(storage, user_id, project_id)
+    if meta is None:
+        return None
+    pst = meta.pcb_status or "draft"
+    if pst not in ("queued", "running"):
+        return None
+
+    prefix = _project_prefix(user_id, project_id)
+    events_prefix = f"{prefix}/events/"
+    last_event = None
+    try:
+        keys = sorted(
+            k for k in storage.list_prefix(events_prefix)
+            if k.endswith(".json") and "/events/" in k
+        )
+        if keys:
+            last_event = storage.read_json(keys[-1])
+    except Exception:
+        last_event = None
+
+    if (last_event or {}).get("event") == "pcb_complete":
+        data = (last_event or {}).get("data") or {}
+        return update_project(
+            storage, user_id, project_id,
+            pcb_status="complete",
+            pcb_cancel_requested=False,
+            pcb_state={
+                "findings": data.get("findings"),
+                "domains": data.get("domains"),
+                "groups": data.get("groups"),
+            },
+        )
+
+    from backend.services import job_runner
+
+    exec_name = meta.pcb_execution_name or f"local/pcb/{project_id}"
+    try:
+        state = job_runner.get_execution_state(exec_name)
+    except Exception:
+        state = "unknown"
+
+    if state in ("pending", "running"):
+        return None
+
+    has_report = storage.exists(f"{prefix}/pcb_report.json")
+    if has_report:
+        return update_project(
+            storage, user_id, project_id,
+            pcb_status="complete",
+            pcb_cancel_requested=False,
+            pcb_state=meta.pcb_state,
+        )
+    return update_project(
+        storage, user_id, project_id,
+        pcb_status="error",
+        pcb_cancel_requested=False,
+        pcb_state={"error": f"PCB worker terminated ({state})"},
+    )
+
+
 # --- CRUD ---
 
 

backend/services/validation.py

@@ -26,7 +26,6 @@ from backend.periscopex.models import (
     ComponentType,
     DesignGraph,
     Finding,
-    LayoutGraph,
     NetType,
     ValidationReport,
 )
@@ -61,8 +60,6 @@ from backend.periscopex.dnp_check import check_dnp_enables
 from backend.periscopex.lifecycle import check_lifecycle, load_lifecycle_dir
 from backend.periscopex.errata_check import check_errata
 from backend.periscopex.internal_features_check import check_internal_features
-from backend.periscopex.placement_check import check_placement
-from backend.periscopex.si_check import check_si
 from backend.periscopex.crystal_cl_check import check_crystal_cl
 from backend.periscopex.nc_pin_check import check_nc_pins
 
@@ -77,7 +74,6 @@ def _is_deterministic(f: Finding) -> bool:
 def _run_deterministic_checks(
     graph: DesignGraph, constraints_map: dict,
     lifecycle_map: dict | None = None,
-    layout: LayoutGraph | None = None,
 ) -> list[Finding]:
     """Run the deterministic graph checks, fail-soft per check — a check bug
     can never break the review or the report."""
@@ -100,8 +96,6 @@ def _run_deterministic_checks(
         ("lifecycle_check", lambda: check_lifecycle(graph, lifecycle_map)),
         ("errata_check", lambda: check_errata(graph, constraints_map)),
         ("internal_features_check", lambda: check_internal_features(graph, constraints_map)),
-        ("placement_check", lambda: check_placement(graph, constraints_map, layout)),
-        ("si_check", lambda: check_si(graph, constraints_map, layout)),
         ("crystal_cl_check", lambda: check_crystal_cl(graph)),
         ("nc_pin_check", lambda: check_nc_pins(graph, constraints_map)),
     ):
@@ -112,17 +106,6 @@ def _run_deterministic_checks(
     return out
 
 
-def _load_layout_graph(graph_path: str) -> LayoutGraph | None:
-    path = Path(graph_path).with_name("layout_graph.json")
-    if not path.is_file():
-        return None
-    try:
-        return LayoutGraph.model_validate_json(path.read_text())
-    except Exception:
-        log.exception("layout_graph.json invalid — skipping placement_check")
-        return None
-
-
 def _assistant_text(blocks) -> str:
     """Best-effort extraction of text content from a completion's raw
     assistant blocks. Provider-agnostic and never raises."""
@@ -312,6 +295,9 @@ async def review_ic_async(
     pdf_dir: Path | None = None,
     storage=None,
     excerpt_cache: dict | None = None,
+    extra_context: str = "",
+    system_prompt: str | None = None,
+    log_stage: str = "review",
 ) -> tuple[ReviewResult, dict]:
     """Review one IC against its datasheet. Async, multi-turn.
 
@@ -373,7 +359,7 @@ async def review_ic_async(
 
             session = await provider.create_session(
                 model=model,
-                system=SYSTEM_PROMPT,
+                system=system_prompt or SYSTEM_PROMPT,
                 # Gemini 2.5/3 thinking models count thoughts against this cap.
                 # 4096 was too tight: U3 (largest IC) burned the entire budget
                 # on thinking and emitted zero visible output, dropping its
@@ -387,13 +373,16 @@ async def review_ic_async(
             )
             try:
                 context = build_component_context(graph, constraints_map, ic_ref)
+                user_text = f"Review this component's usage:\n\n{context}"
+                if extra_context.strip():
+                    user_text += "\n\n" + extra_context.strip()
 
                 initial_msg = Message(
                     role="user",
                     content=[
                         PdfBlock(path=Path(trimmed_pdf), cacheable=True),
                         TextBlock(
-                            text=f"Review this component's usage:\n\n{context}",
+                            text=user_text,
                             cacheable=True,
                         ),
                     ],
@@ -503,7 +492,7 @@ async def review_ic_async(
                                 )
                             if api_logger:
                                 api_logger.log(
-                                    stage="review", identifier=ic_ref,
+                                    stage=log_stage, identifier=ic_ref,
                                     model=model, provider=provider.name,
                                     input_tokens=total_input, output_tokens=total_output,
                                     cache_creation_input_tokens=total_cache_creation,
@@ -607,7 +596,7 @@ async def review_ic_async(
                 trace["duration_ms"] = int((time.monotonic() - t0) * 1000)
                 if api_logger:
                     api_logger.log(
-                        stage="review", identifier=ic_ref,
+                        stage=log_stage, identifier=ic_ref,
                         model=model, provider=provider.name,
                         input_tokens=total_input, output_tokens=total_output,
                         cache_creation_input_tokens=total_cache_creation,
@@ -730,7 +719,7 @@ async def validate_design_async(
         if loaded:
             lifecycle_map.update(loaded)
     deterministic_findings = _run_deterministic_checks(
-        graph, constraints_map, lifecycle_map, layout=_load_layout_graph(graph_path),
+        graph, constraints_map, lifecycle_map,
     )
 
     pdf_dir_path = Path(pdf_dir)