KoalaSync/docs/branch-scope-issue-13-title-privacy.md

Branch Scope: Issue #13 Title Privacy

Temporary planning document for branch codex/issue-13-title-privacy.

IMPORTANT: Delete this file before opening the PR. It is only for branch-local coordination and should not be merged.

Issue

GitHub issue #13 asks for an advanced privacy option that controls whether tab titles and media titles are sent to the KoalaSync relay server.

Goals

• Keep the existing behavior as the default for full backwards compatibility.
• Add a local-only extension setting for shared title privacy.
• Support three modes:
  • Full titles: current behavior.
  • Episode only: send only an extracted episode identifier such as S01E04 or EP004.
  • Hidden: clear shared tab and media titles before they leave the extension.
• Avoid server changes unless absolutely necessary.
• Preserve local title-based behavior where possible, including local episode detection.

Compatibility Notes

• Existing users should keep sending full titles unless they actively change the new setting.
• Existing servers already accept omitted, null, or string title fields.
• The protocol version should not need to change because this is a client-side reduction of optional payload fields.
• Older clients in the same room will keep behaving as before.

Implementation Notes

• Centralize outgoing title filtering in extension/background.js.
• Store the option in chrome.storage.local, not chrome.storage.sync.
• Use the existing episode extraction helper logic for episode-only mode.
• In hidden mode, actively send null for title fields so stale titles are cleared server-side.
• Episode lobby payloads must not leak full titles when privacy mode is hidden.

Verification

• Run the existing verification script.
• Add focused tests for title privacy helpers if the code shape allows it.
• Manually inspect the popup settings layout after adding the select control.