refactor: migrate maildir flows to shared mblaze adapters

[jaromil]

Summary

• remove legacy publish command wiring/module and keep command contract tests for its absence
• centralize Maildir operations behind adapters (maildir_list_messages, maildir_list_folders, maildir_refile)
• migrate parse/filter/search/stats code paths to use adapters and fix mblaze extraction mode handling (sender|recipient|all)
• expand regression coverage for maildir commands, filtering progress, and stats/backup contracts

Behavior notes

• intended user-facing change: publish command is removed
• extraction modes now correctly apply when mblaze is present
• backup path now uses maildir_refile adapter instead of legacy undefined refile path

Validation

• make
• zsh extras/test/run-source.sh
• zsh extras/test/test-addressbook-parse.sh
• zsh extras/test/test-account-wizard.sh
• zsh extras/test/test-bootstrap-paths.sh
• zsh extras/test/test-filtering.sh
• zsh extras/test/test-group-modes.sh
• zsh extras/test/test-sieve-import.sh
• zsh extras/test/test-helpers.sh
• zsh extras/test/test-maildir-commands.sh
• zsh extras/test/test-maildir-stats-backup.sh