fix(web): bundle deps into the server (noExternals) — kill the 47k-file install

The Windows installer ballooned to 154 MB and installed forever because the node-server
bundle externalized the WHOLE @unom/ui dependency tree (payload, lexical, date-fns,
prismjs…) to .output/server/node_modules — 47,567 files / 730 MB copied into Program
Files. Set Nitro `noExternals: true` so every dependency is bundled + tree-shaken into the
server output: .output drops to ~75 files / 10 MB, and the bare external imports
(srvx, seroval…) bun couldn't resolve at runtime are gone — so the console runs on bun
(no node, no node_modules), which is the issue we previously worked around with node.

Windows installer now ships bun.exe + the ~75-file .output (was node.exe + a node_modules
forest) and runs `bun .output\server\index.mjs`:
- windows-host.yml: fetch a pinned portable bun (build tool AND shipped runtime); drop the
  node fetch + the .output/server install; smoke-boot under the bundled bun.
- pack-host-installer.ps1 / punktfunk-host.iss: -NodeExe -> -BunExe; stage {app}\bun\bun.exe.
- web-run.cmd / build-web.ps1: run/restart on bun; docs updated.

Net win everywhere: the Linux .deb shrinks (node still runs the self-contained output), and
the docker web image — which already ran `bun run .output/server/index.mjs` with only
.output copied — is fixed (the externals had no node_modules to resolve at runtime).

Validated locally: noExternals build = 75 files / 10 MB; node AND bun both serve /login
(200) + static assets (200) + gate /api (401).

(A true single binary via `bun build --compile` is blocked for now: Nitro serves public
assets from an import.meta-relative path `--compile` doesn't embed (/$bunfs/public); the
75-file payload is the clean result.)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/vite.config.ts

@@ -46,6 +46,14 @@ export default defineConfig({
       // .deb depend on apt-native `nodejs (>= 20)` instead of vendoring bun. CI still BUILDS with
       // bun; only the runtime target changes. (dev `vite dev` is unaffected.)
       preset: 'node-server',
+      // BUNDLE every dependency into the server output (no externalized node_modules). Three wins:
+      // (1) the .output tree drops from ~47k files / 730 MB (the whole untree-shaken @unom/ui dep
+      // tree — payload, lexical, date-fns…) to a handful of tree-shaken chunks; (2) it makes the
+      // output a self-contained graph `bun build --compile` can fold into ONE native binary (the
+      // Windows installer ships that instead of node + a node_modules forest); (3) it removes the
+      // bare external imports (`srvx`, `seroval`…) bun couldn't resolve at runtime — the reason we
+      // used to need node. node still runs the same self-contained output for the Linux .deb.
+      noExternals: true,
       compatibilityDate: '2026-06-10',
       // Scan server/{middleware,routes} for the auth gate + the /api proxy.
       scanDirs: [serverDir],