feat: make focus items permanent — no date scoping

Focus items now persist until explicitly removed. Removed date
filtering from main query, dedup subqueries, reorder, and sidebar
badge count. Removed date navigation from UI. The focus_date column
remains as metadata but no longer affects display.

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

core/sidebar.py

@@ -40,7 +40,7 @@ async def get_sidebar_data(db: AsyncSession) -> dict:
 
     result = await db.execute(text("""
         SELECT count(*) FROM daily_focus
-        WHERE is_deleted = false AND focus_date = CURRENT_DATE AND completed = false
+        WHERE is_deleted = false AND completed = false
     """))
     focus_count = result.scalar() or 0