uploads-v0.16.0

Minor Changes

• 87f5626: Add uploads github doctor to check whether the GitHub App is subscribed to the webhook events uploads.sh needs (issues, pull_request). A missing subscription previously failed silently — the App's ping stayed green while webhook auto-promotion and title-cache invalidation quietly did nothing.
• 65cb8b9: Add uploads github unlink to release a workspace's GitHub repo binding (self-serve counterpart to uploads github link), and point github link's already-bound-elsewhere output at the remedy.

Patch Changes

• bb149da: uploads attach --branch <name> now rejects a value that looks like a file
  (an existing path on disk, or a name with a media/document extension like
  .png/.pdf) instead of silently swallowing it as the branch name. Fixes
  uploads attach --branch shot.png staging under a branch literally named
  "shot.png" — use uploads attach shot.png --branch (auto-detect the current
  branch) or uploads attach --branch <name> shot.png instead. Ordinary dotted
  branch names like v1.2 or release/1.2 are unaffected.
• 9baf580: Stop falling back to the local gh path when the server declines a comment post with not_authorized (cross-tenant repo binding) — surface the decline with a hint to uploads github link --status instead, since a silent gh fallback would just work around the server-side gate with the human's own credentials.