Manny Wenas Redirect Manager v1.0.1

Bump to v1.0.1: fix subdirectory prefix, DB error handling, README

- Version header and MWRM_VERSION constant updated to 1.0.1
- relative_path(): verify prefix ends on a path boundary (/ or end of string)
  so /blogger is no longer stripped when home is /blog
- save(): check $wpdb->update() and $wpdb->insert() return values;
  return WP_Error with last_error message on failure
- README: remove "scaffold only" wording, document all live features,
  import behaviour, and uninstall data-loss warning

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XQXXU4SWs1xuiqnacgjrn5

Manny Wenas Redirect Manager 1.0.0

v1.0.0

Merge pull request #1 from manfredw-droid/claude/manny-wenas-redirect…