Rebrand Pinscope to Periscope across product and codebase.

Rename the core package to periscopex, update UI/docs/Docker/deploy defaults to periscope.michelebigi.it, and keep legacy version/storage key aliases so existing projects keep working.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/periscopex/si_check.py

@@ -0,0 +1,91 @@
+"""G1 SI: intra-pair skew only when the datasheet gives millimetres.
+
+Pair names (_DP/_DM, _P/_N) only identify which nets to compare. The
+limit is never 3W, USB spec folklore, or a default millimetre.
+"""
+
+from __future__ import annotations
+
+import math
+
+from backend.periscopex.models import DesignGraph, Finding, LayoutGraph, LayoutSegment
+from backend.periscopex.validate import _match_constraints
+
+_PAIR_SUFFIXES = (("_DP", "_DM"), ("_P", "_N"), ("+", "-"))
+
+
+def _seg_len(seg: LayoutSegment) -> float:
+    return math.hypot(seg.end[0] - seg.start[0], seg.end[1] - seg.start[1])
+
+
+def net_length_mm(layout: LayoutGraph, net: str) -> float:
+    return sum(_seg_len(s) for s in layout.segments if s.net == net)
+
+
+def partner_net(name: str) -> str | None:
+    for a, b in _PAIR_SUFFIXES:
+        if name.endswith(a):
+            return name[: -len(a)] + b
+        if name.endswith(b):
+            return name[: -len(b)] + a
+    return None
+
+
+def _length_match_limit_mm(constraints_map: dict, graph: DesignGraph) -> tuple[float, int | None] | None:
+    for comp in graph.components.values():
+        cons = _match_constraints(comp.mpn, constraints_map)
+        if not cons:
+            continue
+        for rule in cons.layout_rules or []:
+            if rule.get("kind") != "length_match":
+                continue
+            mm = rule.get("max_distance_mm")
+            if mm is None:
+                continue
+            return float(mm), rule.get("source_page")
+    return None
+
+
+def check_si(
+    graph: DesignGraph,
+    constraints_map: dict,
+    layout: LayoutGraph | None,
+) -> list[Finding]:
+    if layout is None or not layout.segments:
+        return []
+    limit = _length_match_limit_mm(constraints_map, graph)
+    if limit is None:
+        return []
+    max_mm, page = limit
+    seen: set[tuple[str, str]] = set()
+    findings: list[Finding] = []
+    names = {s.net for s in layout.segments if s.net}
+    for net in names:
+        partner = partner_net(net)
+        if not partner or partner not in names:
+            continue
+        key = tuple(sorted((net, partner)))
+        if key in seen:
+            continue
+        seen.add(key)
+        skew = abs(net_length_mm(layout, net) - net_length_mm(layout, partner))
+        if skew <= max_mm:
+            continue
+        findings.append(Finding(
+            designator="layout",
+            mpn="",
+            aspect="si",
+            finding=(
+                f"Intra-pair skew {skew:.1f} mm on {key[0]}/{key[1]} "
+                f"(datasheet max {max_mm:g} mm)."
+            ),
+            why=f"length_match max_distance_mm={max_mm:g}.",
+            status="ERROR",
+            recommendation="Length-match the differential pair.",
+            source="si_check",
+            rule_id="PE-SI-001",
+            net=net,
+            pins=[],
+            source_page=page,
+        ))
+    return findings