feat: public guest room discovery endpoints (slice 1 for webapp #141)

GET /public/rooms + /public/rooms/{id} — no auth, active rooms only,
operator-private fields stripped. The webapp guest UI needs these because
the existing GET /rooms is admin-scoped; availability + booking POST are
already public. Reuses the public_room_dict strip.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019VUQCfdqiLSsFS2jcGnaFD

views_api.py

@@ -24,6 +24,7 @@ from .models import (
     CreateRoomData,
     Room,
     RoomStatus,
+    public_room_dict,
 )
 from .nostr import service as nostr
 
@@ -189,6 +190,27 @@ async def api_update_settings(
     return await crud.update_settings(settings)
 
 
+# --- public guest discovery (no auth) --------------------------------------
+
+
+@chatelet_api_router.get("/api/v1/public/rooms")
+async def api_public_rooms() -> list[dict]:
+    """Active rooms for guest browsing — operator-private fields stripped."""
+    return [
+        public_room_dict(r)
+        for r in await crud.get_rooms()
+        if r.status == RoomStatus.active
+    ]
+
+
+@chatelet_api_router.get("/api/v1/public/rooms/{room_id}")
+async def api_public_room(room_id: str) -> dict:
+    room = await crud.get_room(room_id)
+    if not room or room.status != RoomStatus.active:
+        raise HTTPException(404, "Room not available")
+    return public_room_dict(room)
+
+
 # --- availability (public read) --------------------------------------------