Fix startup: load Fava settings from DB instead of hardcoded defaults

castle_start() was using CastleSettings() defaults (slug=castle-ledger)
instead of reading the saved settings from the database. This caused all
Fava queries to 404 on instances where the ledger slug differs from the
default (e.g. demo-ledger).

Now loads settings from extension_settings table at startup, falling
back to defaults only if no saved settings exist.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

__init__.py

@@ -38,16 +38,35 @@ def castle_start():
     from .models import CastleSettings
     from .tasks import wait_for_account_sync
 
-    # Initialize Fava client with default settings
-    # (Will be re-initialized if admin updates settings)
-    defaults = CastleSettings()
-    try:
+    async def _init_fava():
+        """Load saved settings from DB, fall back to defaults."""
+        from .crud import db as castle_db
+
+        settings = None
+        try:
+            row = await castle_db.fetchone(
+                "SELECT * FROM extension_settings LIMIT 1",
+                model=CastleSettings,
+            )
+            if row:
+                settings = row
+                logger.info(f"Loaded Castle settings from DB: {settings.fava_url}/{settings.fava_ledger_slug}")
+        except Exception as e:
+            logger.warning(f"Could not load settings from DB: {e}")
+
+        if not settings:
+            settings = CastleSettings()
+            logger.info(f"Using default Castle settings: {settings.fava_url}/{settings.fava_ledger_slug}")
+
         init_fava_client(
-            fava_url=defaults.fava_url,
-            ledger_slug=defaults.fava_ledger_slug,
-            timeout=defaults.fava_timeout
+            fava_url=settings.fava_url,
+            ledger_slug=settings.fava_ledger_slug,
+            timeout=settings.fava_timeout
         )
-        logger.info(f"Fava client initialized: {defaults.fava_url}/{defaults.fava_ledger_slug}")
+        logger.info(f"Fava client initialized: {settings.fava_url}/{settings.fava_ledger_slug}")
+
+    try:
+        asyncio.get_event_loop().create_task(_init_fava())
     except Exception as e:
         logger.error(f"Failed to initialize Fava client: {e}")
         logger.warning("Castle will not function without Fava. Please configure Fava settings.")