Add file badges, menu icons, LSP diagnostics, robust compaction

- Files in chat: preview with type/size badges and file name; attachment chips
- Menu and settings tabs with icons
- Heatmap: distinct colour for empty hours, hourly labels
- Context chip shows used/total tokens (e.g. 221k/240k) plus percent
- LSP client: diagnostics appended to edit/write results and a diagnostics tool
  (typescript-language-server, pyright, rust-analyzer, gopls, clangd; sandboxed)
- Compaction summarizes a plain transcript and retries once on empty output
- files/stat endpoint

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/components/Settings.tsx

@@ -818,6 +818,19 @@ function Raw({ reload }: { reload: () => void }) {
 
 const ADMIN_TABS = ["general", "providers", "agents", "mcp", "permissions", "users", "folders", "tools", "audit", "account", "raw"] as const;
 const USER_TABS = ["general", "account"] as const;
+const TAB_ICONS: Record<string, string> = {
+  general: "⚙️",
+  providers: "🧠",
+  agents: "🤖",
+  mcp: "🔌",
+  permissions: "🛡️",
+  users: "👥",
+  folders: "🗂️",
+  tools: "🧰",
+  audit: "📜",
+  account: "👤",
+  raw: "📝",
+};
 
 export function Settings({ tab, onMenu }: { tab?: string; onMenu: () => void }) {
   const t = useT();
@@ -841,6 +854,9 @@ export function Settings({ tab, onMenu }: { tab?: string; onMenu: () => void })
           <div className="tabs" role="tablist">
             {TABS.map((x) => (
               <button key={x} role="tab" aria-selected={active === x} className={active === x ? "active" : ""} onClick={() => navigate(`/settings/${x}`)}>
+                <span className="nav-icon" aria-hidden>
+                  {TAB_ICONS[x]}
+                </span>
                 {t(`settings.tab.${x}` as Key)}
               </button>
             ))}