feat(ui): mobile-responsive sidebar + rules improvements

- Sidebar: hidden on mobile, opens as slide-out drawer with hamburger
  toggle; auto-closes on navigation; desktop layout unchanged
- Layout: responsive padding accounting for mobile header bar
- Rules: add tag as a condition field (has/not-has tag)
- Rules: apply a single rule via per-rule Apply button
- Rules: splits-from defaults to 2026-01-09

src/app/layout.tsx

@@ -32,7 +32,7 @@ export default function RootLayout({
         <Providers>
           <div className="flex min-h-screen">
             <Sidebar />
-            <main className="flex-1 p-6 overflow-auto">{children}</main>
+            <main className="flex-1 pt-[calc(3.5rem+1rem)] px-3 pb-3 md:p-6 md:pt-6 overflow-auto">{children}</main>
           </div>
         </Providers>
       </body>