build(core): SNOWLUMA_BUILD_SKIP_NATIVES=1 escape hatch for darwin dev

Two architectural cleanups that complement the bridge darwin support in
7343ae6, both opt-in / default-safe:

1) `vite.config.ts` — gate the missing-native build error behind
   `SNOWLUMA_BUILD_SKIP_NATIVES=1`. Default behaviour (no env) still
   throws as before, so the CI invariant "release builds must carry the
   full native set" is untouched. Darwin developers without prebuilt
   `websocket-darwin-arm64.node` (source lives in a separate private
   build repo) can now run `SNOWLUMA_BUILD_SKIP_NATIVES=1 pnpm build`
   and pair it with the runtime `SNOWLUMA_DEV_NO_NATIVE=1` stub at
   `node dist/index.mjs` boot. The qq-hook path (separate addon) is
   independent and unaffected.

2) `packages/core/config/.gitignore` — `runtime.json` is the only
   tracked deploy-time override file in that dir; every other config
   file is per-instance runtime state written by the daemon/dev server
   (admin password hash, EULA consent, per-uin OneBot binding, WebUI
   layout). Previously they showed up as 5 untracked files after every
   `pnpm dev:mode`, polluting `git status` and risking accidental
   commit of local creds via `git add -A`. Pattern: ignore everything
   except `runtime.json` (and the .gitignore itself).

No code paths changed; both are operator-experience fixes for running
SnowLuma on darwin against the nnphook DYLD_INSERT hook.

packages/core/config/.gitignore

@@ -0,0 +1,16 @@
+# Per-instance runtime state written by the dev server / production daemon.
+# `runtime.json` is the only tracked file (the deploy-time overrides for
+# webuiPort, hookAutoLoad, etc); everything else here is operator-private:
+#   * webui.json          — admin password hash + rotation state
+#   * consent.json        — EULA/PRIVACY acceptance per agreement version
+#   * notifications.json  — per-account webhook destinations
+#   * onebot_<uin>.json   — per-uin OneBot transport binding (HTTP/WS ports etc)
+#   * ui.json             — WebUI panel layout per operator
+#
+# Without this ignore file, every `pnpm dev:mode` / `node dist/index.mjs`
+# leaves a 5-file untracked surface in `packages/core/config/` that pollutes
+# `git status` and would accidentally commit local creds if `git add -A` is used.
+
+*
+!.gitignore
+!runtime.json

packages/core/vite.config.ts

@@ -70,6 +70,14 @@ const ffmpegSrcDir = path.resolve(nativeDir, 'ffmpeg');
 // Fail fast if any expected native binary is missing from packages/runtime/native/.
 // vite-plugin-cp only emits a warning on missing source files; we want a hard
 // error so CI can't accidentally ship an incomplete archive.
+//
+// Escape hatch: SNOWLUMA_BUILD_SKIP_NATIVES=1 downgrades the missing-native
+// error to a warning. Use ONLY for local dev on platforms where prebuilt
+// native binaries aren't available yet (e.g. darwin-arm64 — the websocket
+// native source lives in a separate private build repo). The runtime
+// websocket loader has its own `SNOWLUMA_DEV_NO_NATIVE=1` stub that lets
+// the daemon boot without the addon at the cost of WebSocket I/O; the qq-hook
+// path is independent and unaffected.
 const missingNatives = nativeFiles.filter(
   (f) => !fs.existsSync(path.join(nativeDir, f)),
 );
@@ -77,10 +85,15 @@ if (!fs.existsSync(path.join(ffmpegSrcDir, ffmpegAddonFile))) {
   missingNatives.push(`ffmpeg/${ffmpegAddonFile}`);
 }
 if (missingNatives.length > 0) {
-  throw new Error(
-    `Missing native binaries for target ${targetTriple}:\n` +
-    missingNatives.map((f) => `  - ${path.join(nativeDir, f)}`).join('\n'),
-  );
+  const detail = `Missing native binaries for target ${targetTriple}:\n` +
+    missingNatives.map((f) => `  - ${path.join(nativeDir, f)}`).join('\n');
+  if (process.env.SNOWLUMA_BUILD_SKIP_NATIVES === '1') {
+    console.warn(`[vite.config] ${detail}\n` +
+      `  (continuing because SNOWLUMA_BUILD_SKIP_NATIVES=1 — runtime needs ` +
+      `SNOWLUMA_DEV_NO_NATIVE=1 to skip the missing addon at boot)`);
+  } else {
+    throw new Error(detail);
+  }
 }
 
 // Legal docs are served by the WebUI consent gate; a missing one would silently