🚧 Fix facet counts on Messages show 1 per device

api/app.py

@@ -1472,6 +1472,38 @@ def create_app(
         count = row[0] if row is not None else 0
         return {"count": count}
 
+    @app.get(
+        "/messages/facet-counts", tags=["meta"], dependencies=[Depends(authenticate)]
+    )
+    def message_facet_counts() -> dict[str, Any]:
+        """Occurrence counts per IMEI and per device name over ALL messages
+        (not just a page), for the Messages view's filter popovers. Values
+        with zero messages still appear when a settings row exists (merged
+        from imei_map), so the facets list devices that "might occur"."""
+        try:
+            conn = psycopg.connect(config.dsn)
+            try:
+                with conn.cursor() as cur:
+                    cur.execute(
+                        "SELECT imei, count(*) FROM mqtt_messages GROUP BY imei"
+                    )
+                    imei_counts = {row[0]: row[1] for row in cur.fetchall()}
+                    cur.execute(
+                        "SELECT device, count(*) FROM mqtt_messages GROUP BY device"
+                    )
+                    device_counts = {row[0]: row[1] for row in cur.fetchall()}
+                    # devices that exist but have no messages yet: count 0
+                    cur.execute("SELECT imei, meta->>'device' FROM imei_map")
+                    for imei, name in cur.fetchall():
+                        imei_counts.setdefault(imei, 0)
+                        if name:
+                            device_counts.setdefault(name, 0)
+            finally:
+                conn.close()
+        except psycopg.Error as exc:
+            raise _db_unavailable(exc) from exc
+        return {"imei": imei_counts, "device": device_counts}
+
     @app.get("/messages", tags=["data"], dependencies=[Depends(authenticate)])
     def list_messages(
         imei: list[str] | None = Query(