feat: kanban status buttons, task back-nav, RSS UI, weather search, briefing fixes

Project view:
- Add inline status advance buttons on kanban task cards (todo→in_progress,
  in_progress→done); buttons reveal on hover, stop link navigation

Task viewer:
- Back button navigates to task's project instead of /tasks when project_id set
- Esc key navigates to project (or /tasks); blurs focused element first

Quick capture:
- Use user's configured model instead of hardcoded Config.OLLAMA_MODEL
- Remove create_project from classifier prompt (tool not offered, caused
  task-shaped inputs to silently fall through to note fallback)

Briefing scheduler:
- Fix get_event_loop() → get_running_loop() so background thread uses the
  correct hypercorn event loop (jobs were scheduling but never executing)
- Suppress bare greeting when both LLM synthesis lanes return empty

RSS feed UI (SettingsView):
- Show last-fetched age, category badge, and feed URL per row
- Category input field when adding a feed
- Refresh all button: fetches latest items, reloads list, toasts with count
- Enter key submits add-feed form; better empty-state hint with example feeds

Weather tool:
- Accept any city/region name in addition to 'home'/'work'/'all'
- Geocodes via Nominatim + fetches live from Open-Meteo for arbitrary queries

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/fabledassistant/services/briefing_pipeline.py

@@ -274,6 +274,10 @@ async def run_compilation(user_id: int, slot: str, model: str | None = None) ->
         ),
     )
 
+    if not internal_text and not external_text:
+        logger.warning("Briefing compilation produced no content for user %d slot %s", user_id, slot)
+        return ""
+
     greeting = slot_greeting(slot)
     today = internal_data["date"]
     parts = [f"**{greeting} — {today}**", ""]