fix(webui-tauri): re-wire shell to tools/ui after the tools/server/webui rename

Three coupled regressions surfaced when Markus hit super+A after the
2026-05-16 rebase: the Tauri shell binary was returning HTTP 500 on
/index.html because tools/server/public/ had been emptied by the
rebase (master's PR ggml-org#22937 moved the build sink to build/tools/ui/),
and the existing config kept pointing at the old paths.

Fixes in tauri.conf.json:

- beforeBuildCommand now `cd ../../ui && bun run build && copy → public`.
  The old `cd ../webui` path no longer exists; the appended copy step
  keeps tools/server/public/ populated so frontendDist resolves on a
  fresh checkout without manual intervention.
- beforeDevCommand and devUrl updated to match (and to bind 127.0.0.1
  rather than localhost so the dev server doesn't accidentally land on
  ::1).
- Window URL changed from http://localhost:5173/... → http://127.0.0.1:5173/...
  Sidesteps webkit2gtk's IPv6-first localhost resolution entirely. The
  embedded tiny-http server is already pinned IPv4 in src/lib.rs:73, so
  this makes both ends speak v4 explicitly and any future IPv6 squatter
  on 5173 can't intercept the webview.

.gitignore: tools/server/public/ is now a pure build sink, and the
tracked tts-default-ref.mp3 it carried was a stale duplicate of
tools/ui/static/tts-default-ref.mp3 (the SvelteKit canonical static).
Untracked it; the build step recopies the canonical file each time.

Diagnosed and fixed jointly with snoop-kube (cloud) and inventory-dev
(squatter cleanup) via /tmp/app-launch-summit.md.

Author: marksverdhei

.gitignore

@@ -99,6 +99,11 @@
 /tools/ui/node_modules
 /tools/ui/dist
 
+# Build sink for the Tauri shell — beforeBuildCommand copies
+# build/tools/ui/dist/* into here so frontendDist resolves. Tracked
+# source assets live in tools/ui/static/.
+/tools/server/public/
+
 # Python
 
 /.venv

tools/server/public/tts-default-ref.mp3

@@ -5,15 +5,15 @@
   "identifier": "com.heiervang.htllama.webui",
   "build": {
     "frontendDist": "../../public",
-    "devUrl": "http://localhost:5173",
-    "beforeDevCommand": "cd ../webui && bun run dev -- --host localhost",
-    "beforeBuildCommand": "cd ../webui && bun run build"
+    "devUrl": "http://127.0.0.1:5173",
+    "beforeDevCommand": "cd ../../ui && bun run dev -- --host 127.0.0.1",
+    "beforeBuildCommand": "cd ../../ui && bun run build && mkdir -p ../server/public && cp -r ../../build/tools/ui/dist/. ../server/public/"
   },
   "app": {
     "windows": [
       {
         "title": "ht-llama.cpp",
-        "url": "http://localhost:5173/index.html#/",
+        "url": "http://127.0.0.1:5173/index.html#/",
         "width": 1280,
         "height": 860,
         "resizable": true,