feat(memory): add automated nightly consolidation at 4:00 AM UTC

Step 2 of memory system overhaul: automated scheduling.

- New consolidation_scheduler.py: run_nightly_consolidation() function that
  checks Cat health, triggers consolidation via WebSocket, and tracks
  run history with success/failure stats
- bot.py on_ready: register APScheduler cron job (hour=4, minute=0)
  alongside the existing daily DM analysis job
- routes/memory.py: expose consolidation status (last_run, last_result,
  last_error, is_running, total_runs, successful_runs) in the
  /memory/status API response
- Web UI: show consolidation schedule info (last run time, success/fail,
  run counts) below the manual consolidate button, with 'running now'
  indicator when active

The 'sleep consolidation' metaphor is now actually automated instead of
being manual-only.

bot/bot.py

@@ -122,6 +122,17 @@ async def on_ready():
     else:
         logger.warning("OWNER_USER_ID not set, DM analysis feature disabled")
 
+    # Schedule nightly memory consolidation (runs at 4 AM UTC every day)
+    from utils.consolidation_scheduler import run_nightly_consolidation
+    globals.scheduler.add_job(
+        run_nightly_consolidation,
+        'cron',
+        hour=4,
+        minute=0,
+        id='nightly_consolidation'
+    )
+    logger.info("🌙 Scheduled nightly memory consolidation at 4:00 AM UTC")
+
     # Setup autonomous speaking (now handled by server manager)
     setup_autonomous_speaking()
     load_last_sent_tweets()