fix(v0.8.5): pin PyPI publisher packages-dir to .dist/ + sync_mirrors path

The v0.8.4 root-cleanup hid the build output dir to .dist/ and
moved scripts/ → .scripts/, but two CI/release artifacts still
pointed at the legacy paths:

1. .github/workflows/release.yml — pypa/gh-action-pypi-publish
   defaults to dist/ for the package upload directory. Without
   an explicit packages-dir, the v0.8.5 release ran 'python -m
   build --outdir .dist' successfully but the publish step
   reported "no Python distribution packages to publish in
   the directory 'dist/'" and failed. Add packages-dir: .dist/.

2. .scripts/build_plugin.py — the defense-in-depth mirror-sync
   step on line 129 referenced repo_root/'scripts'/sync_plugin_mirrors.py
   which no longer exists (relocated to .scripts/). The build still
   succeeded because the check is non-fatal (a missing script just
   skips), but the .zip bundle wouldn't have benefited from the
   pre-flight mirror parity check.

Tag v0.8.5 was deleted from origin so this commit can be the
new tag target — re-tag immediately after this lands.

Author: Yanjun

.github/workflows/release.yml

@@ -131,6 +131,10 @@ jobs:
         uses: pypa/gh-action-pypi-publish@cef221092ed1bacb1cc03d23a2d87d1d172e277b  # release/v1
         with:
           skip-existing: true
+          # v0.8.5 — build now writes to .dist/ (per the v0.8.4 root-
+          # cleanup). The PyPA publish action defaults to dist/, so we
+          # point it at the hidden directory explicitly.
+          packages-dir: .dist/
 
       - name: Build Cowork .zip plugin bundle
         # v0.5.20: produce the drag-drop bundle Cowork users upload

.scripts/build_plugin.py

@@ -99,7 +99,7 @@ def main(argv: list[str] | None = None) -> int:
         "--out",
         type=Path,
         default=None,
-        help="Destination directory (default: <repo-root>/dist).",
+        help="Destination directory (default: <repo-root>/.dist/).",
     )
     p.add_argument(
         "--version",
@@ -126,7 +126,8 @@ def main(argv: list[str] | None = None) -> int:
     # `.claude/<dir>/X.md` (project) and `<repo>/<dir>/X.md` (bundle)
     # MUST contain identical bytes. See scripts/sync_plugin_mirrors.py
     # docstring + ``L2_DOCTRINE/boundary.md`` § "Legacy import shims".
-    sync_script = repo_root / "scripts" / "sync_plugin_mirrors.py"
+    # v0.8.4 root-cleanup (2026-05-12): scripts/ relocated to .scripts/.
+    sync_script = repo_root / ".scripts" / "sync_plugin_mirrors.py"
     if sync_script.is_file():
         rc = subprocess.call(
             [sys.executable, str(sync_script)],