restructure to react spa + hono api, fix missing server/ and lib/

rewrite from monolithic hono jsx to react 19 spa with tanstack router
+ hono json api backend. add scan, review, execute, nodes, and setup
pages. multi-stage dockerfile (node for vite build, bun for runtime).

previously, server/ and src/shared/lib/ were silently excluded by
global gitignore patterns (/server/ from emacs, lib/ from python).

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

src/routes/scan.tsx

@@ -0,0 +1,6 @@
+import { createFileRoute } from '@tanstack/react-router';
+import { ScanPage } from '~/features/scan/ScanPage';
+
+export const Route = createFileRoute('/scan')({
+	component: ScanPage,
+});