correlator/intelligence: close the incident-clearance gap (dispatch-to-10-8 lifecycle)

Two independent fixes, found by tracing why incidents never actually close
(only 2/281 incidents in 5 correlation debug windows ever got a non-empty
units_cleared; 183 resolved via the 90-min idle sweep instead of a real clear):

1. Pattern B (re-dispatch accept, no explicit 10-8): reassignment=True already
   fired correctly and suppressed the unit from re-linking to its prior
   incident, but nothing ever released the unit FROM that incident — it just
   sat "active" until the idle sweep timed it out. _release_reassigned_units
   now scans other active incidents for unit overlap on a reassignment and
   clears the unit there, reusing the same units_active/units_cleared merge
   (factored out as _apply_unit_clearance) that explicit 10-8 extraction uses.

2. Pattern A (self-clear) extraction was inconsistent for two reasons: no
   per-system unit ID format awareness anywhere in the pipeline (formats vary
   by department with zero shared convention), and the cleared_units prompt
   rule only accepted a unit self-reporting, missing dispatch confirming a
   unit's status back to them. Added system.unit_format_hint (owner-authored
   free text, GET/PUT /systems/{id}/unit-format, no auto-induction yet) fed
   into the extraction prompt, and broadened the cleared_units rule while
   still requiring an identifiable unit ID (guards against bare "10-8"/"clear"
   noise, including Whisper hallucination runs already caught upstream by
   _is_garbage_transcript).

Verified: 401 pass, 0 fail (local Linux venv ~/venvs/drb-5c — see CLAUDE.md
testing-reality note).

server-26#pending — not yet filed, Gitea unreachable from this sandbox.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

drb-c2-core/app/routers/systems.py

@@ -24,6 +24,10 @@ class TenCodesBody(BaseModel):
     ten_codes: Dict[str, str]
 
 
+class UnitFormatBody(BaseModel):
+    unit_format_hint: str
+
+
 class PendingTermBody(BaseModel):
     talkgroup_id: int
     term: str
@@ -155,6 +159,38 @@ async def update_ten_codes(
     return {"ok": True, "ten_codes": body.ten_codes}
 
 
+# ── Unit ID format hint ─────────────────────────────────────────────────────────
+
+@router.get("/{system_id}/unit-format")
+async def get_unit_format(system_id: str):
+    """Return the unit-ID format hint for a system."""
+    system = await fstore.doc_get("systems", system_id)
+    if not system:
+        raise HTTPException(404, f"System '{system_id}' not found.")
+    return {"unit_format_hint": system.get("unit_format_hint") or ""}
+
+
+@router.put("/{system_id}/unit-format")
+async def update_unit_format(
+    system_id: str,
+    body: UnitFormatBody,
+    _: dict = Depends(require_admin_token),
+):
+    """
+    Set the free-text unit-ID format hint fed into intelligence.py's
+    extraction prompt (server-26#<pending>). Departments have no shared unit
+    ID convention — e.g. "5-David"/bare "David" vs "SAM-1"/"airport-3" — and
+    the extraction prompt has no way to recognise a format it hasn't been
+    told about. Own route for the same reason ten-codes has one: not carried
+    by the systems form, so folding it into PUT /{id} would wipe it.
+    """
+    existing = await fstore.doc_get("systems", system_id)
+    if not existing:
+        raise HTTPException(404, f"System '{system_id}' not found.")
+    await fstore.doc_update("systems", system_id, {"unit_format_hint": body.unit_format_hint})
+    return {"ok": True, "unit_format_hint": body.unit_format_hint}
+
+
 # ── Area context ──────────────────────────────────────────────────────────────
 
 @router.get("/{system_id}/area-context")