feat: add column sort, SQL formatter, table stats, insert dialog, saved queries & sessions monitor

- Column sort by header click in table view (ASC/DESC/none cycle, server-side)
- SQL formatter with Format button and Shift+Alt+F keybinding (sql-formatter)
- Table size and row count display in schema tree via pg_class
- Insert row dialog with column type hints and auto-skip for identity columns
- Saved queries (bookmarks) with CRUD backend, sidebar panel, and save dialog
- Active sessions monitor (pg_stat_activity) with auto-refresh, cancel & terminate

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

src/lib/tauri.ts

@@ -4,10 +4,13 @@ import type {
   QueryResult,
   PaginatedQueryResult,
   SchemaObject,
+  ColumnDetail,
   ColumnInfo,
   ConstraintInfo,
   IndexInfo,
   HistoryEntry,
+  SavedQuery,
+  SessionInfo,
   DatabaseInfo,
   CreateDatabaseParams,
   RoleInfo,
@@ -79,6 +82,12 @@ export const getTableColumns = (
   table: string
 ) => invoke<ColumnInfo[]>("get_table_columns", { connectionId, schema, table });
 
+export const getColumnDetails = (
+  connectionId: string,
+  schema: string,
+  table: string
+) => invoke<ColumnDetail[]>("get_column_details", { connectionId, schema, table });
+
 export const getTableConstraints = (
   connectionId: string,
   schema: string,
@@ -151,6 +160,16 @@ export const getHistory = (params?: {
 
 export const clearHistory = () => invoke<void>("clear_history");
 
+// Saved Queries
+export const listSavedQueries = (params?: { search?: string }) =>
+  invoke<SavedQuery[]>("list_saved_queries", { search: params?.search });
+
+export const saveQuery = (query: SavedQuery) =>
+  invoke<void>("save_query", { query });
+
+export const deleteSavedQuery = (id: string) =>
+  invoke<void>("delete_saved_query", { id });
+
 // Completion schema
 export const getCompletionSchema = (connectionId: string) =>
   invoke<Record<string, Record<string, string[]>>>(
@@ -201,3 +220,13 @@ export const grantRevoke = (connectionId: string, params: GrantRevokeParams) =>
 
 export const manageRoleMembership = (connectionId: string, params: RoleMembershipParams) =>
   invoke<void>("manage_role_membership", { connectionId, params });
+
+// Sessions
+export const listSessions = (connectionId: string) =>
+  invoke<SessionInfo[]>("list_sessions", { connectionId });
+
+export const cancelQuery = (connectionId: string, pid: number) =>
+  invoke<boolean>("cancel_query", { connectionId, pid });
+
+export const terminateBackend = (connectionId: string, pid: number) =>
+  invoke<boolean>("terminate_backend", { connectionId, pid });