ci: SHA-pin secret-bearing third-party actions + audit the web dep tree

- Pin android-actions/setup-android, appleboy/scp-action, and
  appleboy/ssh-action to commit SHAs (version kept in a trailing comment).
  These run in jobs holding the Android signing keystore, Play
  service-account, and deploy SSH key, so a moved tag on a third-party
  action could exfiltrate them.
- Add a bun-audit job to audit.yml over web/bun.lock — the console holds
  the login gate, session sealing, and mgmt token, so its deps matter too
  — and trigger the workflow on web/bun.lock changes alongside Cargo.lock.

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

.gitea/workflows/docker.yml

@@ -86,7 +86,10 @@ jobs:
       - uses: actions/checkout@v4
 
       - name: Sync compose file
-        uses: appleboy/scp-action@v0.1.7
+        # SHA-pinned (not tag-pinned): this action receives DEPLOY_SSH_KEY + host/user/port, so a
+        # moved tag would mean credential exfiltration. v0.1.7 = 917f8b8. Bump both the SHA and the
+        # trailing version together when upgrading.
+        uses: appleboy/scp-action@917f8b81dfc1ccd331fef9e2d61bdc6c8be94634 # v0.1.7
         with:
           host: ${{ secrets.DEPLOY_HOST }}
           username: ${{ secrets.DEPLOY_USER }}
@@ -97,7 +100,8 @@ jobs:
           overwrite: true
 
       - name: Pull and start docs
-        uses: appleboy/ssh-action@v1.2.5
+        # SHA-pinned: receives DEPLOY_SSH_KEY + REGISTRY_TOKEN (see the scp step above). v1.2.5 = 0ff4204.
+        uses: appleboy/ssh-action@0ff4204d59e8e51228ff73bce53f80d53301dee2 # v1.2.5
         env:
           REGISTRY_TOKEN: ${{ secrets.REGISTRY_TOKEN }}
         with: