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/components/layout/Sidebar.tsx

@@ -2,10 +2,11 @@ import { useState } from "react";
 import { Input } from "@/components/ui/input";
 import { SchemaTree } from "@/components/schema/SchemaTree";
 import { HistoryPanel } from "@/components/history/HistoryPanel";
+import { SavedQueriesPanel } from "@/components/saved-queries/SavedQueriesPanel";
 import { AdminPanel } from "@/components/management/AdminPanel";
 import { Search } from "lucide-react";
 
-type SidebarView = "schema" | "history" | "admin";
+type SidebarView = "schema" | "history" | "saved" | "admin";
 
 export function Sidebar() {
   const [view, setView] = useState<SidebarView>("schema");
@@ -34,6 +35,16 @@ export function Sidebar() {
         >
           History
         </button>
+        <button
+          className={`flex-1 px-3 py-1.5 font-medium ${
+            view === "saved"
+              ? "bg-background text-foreground"
+              : "text-muted-foreground hover:text-foreground"
+          }`}
+          onClick={() => setView("saved")}
+        >
+          Saved
+        </button>
         <button
           className={`flex-1 px-3 py-1.5 font-medium ${
             view === "admin"
@@ -65,6 +76,8 @@ export function Sidebar() {
         </>
       ) : view === "history" ? (
         <HistoryPanel />
+      ) : view === "saved" ? (
+        <SavedQueriesPanel />
       ) : (
         <AdminPanel />
       )}