chore(release): v0.3.3 (#267)

Patch release. Bumps version across all sources + lock files; adds [0.3.3]
CHANGELOG.

Ships:
- #262 — Settings → About now shows the server's CPU architecture (was the
  client browser's platform, e.g. "Win32", in Docker).
- Validates the bash-3.2 checksum CI fix on a real release (the macOS
  SHA256SUMS should now upload automatically).

Tagging v0.3.3 triggers release.yml (desktop) + docker.yml (GHCR
:0.3.3/:0.3/:latest).

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

backend/core/version.py

@@ -12,4 +12,4 @@ from importlib.metadata import PackageNotFoundError, version
 try:
     APP_VERSION = version("omnivoice")
 except PackageNotFoundError:  # non-installed source checkout
-    APP_VERSION = "0.3.2"
+    APP_VERSION = "0.3.3"