Add terminal client, memory, model fallback, version and install improvements

- codecraft: full-screen terminal client (ratatui) – local tools and files,
  models via the CodeCraft server gateway or own providers (standalone with a
  guided setup), slash commands, @files, permission dialogs, resume, update
- Static Linux CLI builds (x86_64/aarch64, cargo-zigbuild) served by the
  server: /cli/install.sh and /cli/download/<target>
- Project memory (remember tool, .codecraft/memory.md) and personal memory
- Model fallback when a host is unreachable or a budget is used up
- Version/commit in UI and health, daily release check, "What's new" dialog
- PWA: install button, maskable icon, manifest id and screenshots
- Case-insensitive detection of connection errors for retries

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

web/src/App.tsx

@@ -15,6 +15,7 @@ import { Jobs } from "./components/Jobs";
 import { Spinner, useTitleActivity } from "./components/Activity";
 import { DialogHost } from "./dialogs";
 import { startPrefsSync } from "./prefsSync";
+import { WhatsNew } from "./components/WhatsNew";
 
 // The file manager (editor, git) is loaded on demand to keep the chat small.
 const Files = lazy(() => import("./components/Files").then((m) => ({ default: m.Files })));
@@ -31,7 +32,7 @@ export function App() {
   const refresh = async () => {
     try {
       const i = await get<Info>("/info");
-      setState(() => ({ me: i.user }));
+      setState(() => ({ me: i.user, update: i.update ?? null }));
       if (i.user) {
         await loadSessions();
         void startPrefsSync();
@@ -70,6 +71,7 @@ export function App() {
       <>
         <Login info={info} onSuccess={refresh} />
         <DialogHost />
+      {info?.user && <WhatsNew version={info.version} />}
       </>
     );