feat(db): add saved_filters table and CRUD operations

Add database schema and SQL queries for generic saved filters system
that allows users to save custom filter presets for any resource type.

Database Schema:
- Add saved_filters table with user_id, name, resource_type, filters (JSONB)
- Create composite index on (user_id, resource_type) for efficient lookups
- Create index on (user_id, name) for future name search feature
- Add update_updated_at_column() trigger to auto-update timestamps
- Make trigger creation idempotent with DROP TRIGGER IF EXISTS

SQL Queries (5 new queries):
- GetSavedFilters: List all filters for user + resource type
- GetSavedFilterByID: Retrieve single filter by ID
- CreateSavedFilter: Create new saved filter
- UpdateSavedFilter: Update filter name/criteria
- DeleteSavedFilter: Remove saved filter

Design Decisions:
- Generic resource_type field supports any resource (media-items, collections, devices)
- JSONB filters field allows flexible schema without migrations
- User-scoped via JWT (user_id foreign key with CASCADE delete)
- Automatic updated_at timestamp via database trigger

Generated Code:
- database.SavedFilters model (10 fields including JSONB filters)
- All 5 CRUD query functions with proper parameter types
- pgtype.UUID wrappers for UUID parameters

Part of: Saved Filters Implementation (Phase 1: Database)
Related: #saved-filters-feature

internal/database/querier.go

@@ -72,6 +72,7 @@ type Querier interface {
 	CreateReadingHistory(ctx context.Context, arg CreateReadingHistoryParams) (ReadingHistory, error)
 	// Refresh Tokens queries
 	CreateRefreshToken(ctx context.Context, arg CreateRefreshTokenParams) (RefreshTokens, error)
+	CreateSavedFilter(ctx context.Context, arg CreateSavedFilterParams) (SavedFilters, error)
 	// Conflict Resolution
 	CreateSyncConflict(ctx context.Context, arg CreateSyncConflictParams) (SyncConflicts, error)
 	CreateSyncHistoryEntry(ctx context.Context, arg CreateSyncHistoryEntryParams) (SyncQueue, error)
@@ -104,6 +105,7 @@ type Querier interface {
 	DeleteMediaNote(ctx context.Context, id pgtype.UUID) error
 	DeleteMediaRating(ctx context.Context, arg DeleteMediaRatingParams) error
 	DeleteReadingProgress(ctx context.Context, arg DeleteReadingProgressParams) error
+	DeleteSavedFilter(ctx context.Context, arg DeleteSavedFilterParams) error
 	DeleteSyncConflict(ctx context.Context, id pgtype.UUID) error
 	DeleteSyncQueueItem(ctx context.Context, id pgtype.UUID) error
 	// Delete system config
@@ -212,6 +214,8 @@ type Querier interface {
 	GetRecentlyAddedItems(ctx context.Context, arg GetRecentlyAddedItemsParams) ([]MediaItems, error)
 	GetRecentlyReadItems(ctx context.Context, arg GetRecentlyReadItemsParams) ([]MediaItems, error)
 	GetRefreshToken(ctx context.Context, token pgtype.UUID) (GetRefreshTokenRow, error)
+	GetSavedFilterByID(ctx context.Context, arg GetSavedFilterByIDParams) (SavedFilters, error)
+	GetSavedFilters(ctx context.Context, arg GetSavedFiltersParams) ([]SavedFilters, error)
 	GetStuckSyncQueueItems(ctx context.Context) ([]SyncQueue, error)
 	GetSyncConflict(ctx context.Context, id pgtype.UUID) (SyncConflicts, error)
 	GetSyncQueueItem(ctx context.Context, id pgtype.UUID) (SyncQueue, error)
@@ -328,6 +332,7 @@ type Querier interface {
 	UpdateMediaRating(ctx context.Context, arg UpdateMediaRatingParams) (MediaRatings, error)
 	UpdatePassword(ctx context.Context, arg UpdatePasswordParams) error
 	UpdateReadingProgress(ctx context.Context, arg UpdateReadingProgressParams) (ReadingProgress, error)
+	UpdateSavedFilter(ctx context.Context, arg UpdateSavedFilterParams) (SavedFilters, error)
 	UpdateSyncQueueItemStatus(ctx context.Context, arg UpdateSyncQueueItemStatusParams) (SyncQueue, error)
 	UpdateSystemSetting(ctx context.Context, arg UpdateSystemSettingParams) error
 	// Update universal progress