[nobump] Unlocked Restrictions: screenshots, copy-forwarding, protected-chat lock

Replaces the pluginBase sample with the plugin:
- remove FLAG_SECURE (FlagSecureReason + Window.setFlags) for screenshots
- unlock forward/copy/save UI in protected chats and re-send protected
  messages as copies from the user's account (media re-uploaded, albums
  regrouped, bot-only parts dropped)
- red lock before protected chats' names in the chat list, header and info
- settings toggles for all three
- verify_bundle.py rewritten for the plugin
- bundle.py enables the git hooks on first run; README documents them

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

scripts/pre-commit

@@ -1,6 +1,9 @@
 #!/usr/bin/env python3
 """Increment the patch component of plugin.json's version as part of the commit.
 
+Enabled per clone by tools/bundle.py, which sets `core.hooksPath scripts` on its
+first run (git never enables hooks from repository content by itself).
+
 Runs as a pre-commit hook, which is the only commit hook whose `git add` is
 picked up by the commit currently being created: