fix(dist): ship a self-contained bundle so it installs from the registry

The unscoped package lives on the Gitea npm registry but its deps span two
registries (`@punktfunk/host` on Gitea, `effect`/`undici` on npmjs). Installing
by name with `--registry <gitea>` sets the default registry for the whole tree,
so `effect` 404s (Gitea doesn't proxy npm), and an unscoped name can't be
scope-mapped. Fix: bundle the backend into ONE self-contained `dist/index.js`
(+ `dist/cli.js`) via `bun build --target=bun` with `@punktfunk/host` + `effect`
inlined — mirroring the scripting runner. The published package now has zero
runtime dependencies and installs with a single `--registry` flag.

- build → `bun build src/{index,cli}.ts --target=bun --outdir dist --external undici`
- @punktfunk/host + effect → devDependencies (bundled, not resolved at install)
- resolveUiDir(): walk to the SPA dir so staticDir works in the bundled
  (dist/index.js) and unbundled (dist/server/index.js) layouts
- version 0.1.0 → 0.1.1

Verified: the bundle loads + scans/detects/previews with NO node_modules present.

bun.lock

@@ -4,13 +4,11 @@
   "workspaces": {
     "": {
       "name": "punktfunk-plugin-rom-manager",
-      "dependencies": {
-        "@punktfunk/host": "^0.1.0",
-        "effect": "^4.0.0-beta.98",
-      },
       "devDependencies": {
         "@biomejs/biome": "^2.5.2",
+        "@punktfunk/host": "^0.1.0",
         "@types/bun": "^1.3.0",
+        "effect": "^4.0.0-beta.98",
         "typescript": "^5.9.3",
       },
     },