feat: initial ROM & emulator manager plugin (M0–M5)

A punktfunk-plugin-* package that scans ROM directories, maps them to
emulators, fetches box art, and reconciles them into the host game library
under provider id `rom-manager` — with a console-hosted web UI.

Engine (pure, unit-tested core):
- Table-driven platform registry (~25 consoles) + emulator registry with
  best-effort per-OS detection (PATH / Flatpak / known paths) and RetroArch
  core discovery.
- Scanner with disc folding (m3u/cue/gdi), archive gating, excludes.
- No-Intro title parsing + optional per-platform region dedupe.
- Security-critical quoting seam: POSIX single-quote + Windows double-quote
  with hostile-name refusal; ROM filenames never reach a shell un-quoted.
- Pure desired-state reconcile (stable external_ids, scale guard, fingerprint
  skip) → full-replace PUT /library/provider/rom-manager.

Box art (like Steam ROM Manager): SteamGridDB primary (portrait/hero/logo/
header, fuzzy match, operator API key) behind a provider seam, with keyless
libretro-thumbnails as the zero-setup fallback (`auto` default).

UI: console-hosted via the SDK `servePluginUi` (zero plugin-side auth) with a
plugin-local REST/SSE API and a self-contained React SPA (Setup / Emulators /
Games / Sync). Standalone password-gated fallback for host-only installs.

CLI: scan / detect / preview / sync / uninstall / set-password.

48 engine tests, typecheck + biome clean, SPA builds. Verified end-to-end:
scan → detect → reconcile PUT, fingerprint idempotence, and the standalone
UI serving SPA + REST.

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

bunfig.toml

@@ -0,0 +1,6 @@
+# Resolve the `@punktfunk` scope from the Gitea npm registry (like `@punktfunk/host` itself).
+# During local development the SDK is consumed via `bun link @punktfunk/host` (the `link:` in
+# package.json) so this only matters once the plugin is installed from the registry — but it's
+# committed so `bun add punktfunk-plugin-rom-manager` resolves the dependency out of the box.
+[install.scopes]
+"@punktfunk" = "https://git.unom.io/api/packages/unom/npm/"