feat: Add accounting period selector for all views

- Add PeriodSelectorMini component for global period selection
- Add accountingPeriod store for shared period state
- Add calendar service/router/model for available periods API
- Update Dashboard, Invoices, Trial Balance, Bank/Cash Register views
  to respect selected period
- Fix Trial Balance navigation sync bug (period now syncs on mount)
- Update backend services to accept luna/an parameters

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

reports-app/backend/app/cache/config.py

@@ -26,6 +26,7 @@ class CacheConfig:
     ttl_invoices_summary: int
     ttl_treasury: int
     ttl_trial_balance: int
+    ttl_calendar_periods: int
 
     # Maintenance
     cleanup_interval: int
@@ -58,6 +59,7 @@ class CacheConfig:
             ttl_invoices_summary=int(os.getenv('CACHE_TTL_INVOICES_SUMMARY', '900')),
             ttl_treasury=int(os.getenv('CACHE_TTL_TREASURY', '600')),
             ttl_trial_balance=int(os.getenv('CACHE_TTL_TRIAL_BALANCE', '600')),
+            ttl_calendar_periods=int(os.getenv('CACHE_TTL_CALENDAR_PERIODS', '3600')),
 
             # Maintenance
             cleanup_interval=int(os.getenv('CACHE_CLEANUP_INTERVAL', '3600')),
@@ -82,5 +84,6 @@ class CacheConfig:
             'invoices_summary': self.ttl_invoices_summary,
             'treasury': self.ttl_treasury,
             'trial_balance': self.ttl_trial_balance,
+            'calendar_periods': self.ttl_calendar_periods,
         }
         return ttl_map.get(cache_type, self.default_ttl)