[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/post-commit

@@ -1,5 +1,6 @@
 #!/bin/sh
-# Companion to scripts/pre-commit.
+# Companion to scripts/pre-commit. Both are enabled per clone by tools/bundle.py
+# (it sets `core.hooksPath scripts` on its first run).
 #
 # `git commit -- <pathspec>` (also how some IDEs commit a file selection) builds
 # the commit from a temporary index. The pre-commit bump therefore lands in the