Stop logging message composer contents

[Xare123]

Problem

The composer logged the full draft text on every edit, placing message contents in plaintext diagnostic logs.

Change

Remove the per-keystroke content log. No composer behavior, annotation handling, storage, or sending logic changes.

Validation

• one-file, one-line deletion
• git diff --check passes
• focused analyzer reports only pre-existing warnings in the controller

Privacy

This reduces sensitive message exposure. It does not add replacement content logging.