feat(dashboard_api): wire GET /webhook/inc-dashboard route

Thin passthrough over reporting.fn_inc_dashboard (fleettickets migration 09),
powering the FleetOps live INC map (open + windowed-closed + metrics). Mirrors
/webhook/tickets for auth/connection and returns the function's jsonb unchanged.

Params: cluster, status, window (today|week|month|custom), from/to (custom).
Validates window enum, custom-requires-from/to, ISO-8601 from/to, and from<to
(400 on failure). Matches docs/dashboard-api-contract.md from the fleettickets repo.

Verified end-to-end against the prod DB (read-only): default/week/cluster
filters return correct payloads; bad window and custom-without-bounds → 400.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

dashboard_api_rev.py

@@ -43,7 +43,7 @@ from urllib.parse import parse_qs
 
 import psycopg2
 import psycopg2.extras
-from fastapi import FastAPI, Request
+from fastapi import FastAPI, Query, Request
 from fastapi.encoders import jsonable_encoder
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import JSONResponse
@@ -304,6 +304,70 @@ def tickets(
         )
 
 
+# ── INC operations dashboard ──────────────────────────────────────────────────
+# Thin passthrough over reporting.fn_inc_dashboard (fleettickets migration 09):
+# returns { window, open: GeoJSON, closed: GeoJSON, metrics, freshness } for the
+# FleetOps live INC map. open = all currently-open INC tickets (not time-filtered);
+# closed = closures within the selected window; metrics react to the selection.
+# Vehicle positions/routes are overlaid by the SPA (FleetNow), not this endpoint.
+_INC_WINDOWS = {"today", "week", "month", "custom"}
+
+
+def _bad_request(msg):
+    return JSONResponse({"error": {"type": "bad_request", "message": msg}}, status_code=400)
+
+
+@app.get("/webhook/inc-dashboard")
+def inc_dashboard(
+    cluster: str | None = None,   # exact tickets.inc.cluster (UPPERCASE), blank = all
+    status: str | None = None,    # exact normalized_status, blank = all
+    window: str = "today",        # today | week | month | custom (calendar EAT)
+    from_: str | None = Query(None, alias="from"),  # custom start (inclusive), ISO-8601
+    to: str | None = None,                          # custom end (exclusive), ISO-8601
+):
+    # Validation (mirrors the contract). The SQL treats any from/to as a custom
+    # window; presets resolve to EAT calendar bounds inside the function.
+    if window not in _INC_WINDOWS:
+        return _bad_request("window must be one of today|week|month|custom")
+    f, t = _clean(from_), _clean(to)
+    if window == "custom" and not f and not t:
+        return _bad_request("custom window requires from and/or to")
+
+    def _parse(v):
+        if not v:
+            return None
+        try:
+            return datetime.fromisoformat(v)
+        except ValueError:
+            return False
+
+    pf, pt = _parse(f), _parse(t)
+    if pf is False or pt is False:
+        return _bad_request("from/to must be ISO-8601 timestamps with an offset/Z")
+    if pf and pt and pf >= pt:
+        return _bad_request("from must be earlier than to")
+
+    try:
+        with get_conn() as conn:
+            with conn.cursor() as cur:
+                cur.execute(
+                    "SELECT reporting.fn_inc_dashboard(%s, %s, %s, %s, %s)",
+                    (_clean(cluster), _clean(status), window, f, t),
+                )
+                payload = cur.fetchone()[0] or {}
+        return JSONResponse(payload)  # jsonb body returned unchanged
+    except Exception:
+        log.exception("inc-dashboard failed")
+        return JSONResponse(
+            {
+                "error": {
+                    "type": "unknown",
+                    "message": "INC dashboard is unavailable. Try again in a few seconds.",
+                }
+            }
+        )
+
+
 # ── Fleet trips (#002) ───────────────────────────────────────────────────────
 
 _FILTER_OPTIONS_SQL = """