Initial build: Asterisk voicemail transcription + portal

- mailcmd replacement (vm_mailcmd.py): faster-whisper transcription (CPU int8),
  extractive summary + intent tags + spoken-digit number extraction,
  multipart/alternative HTML email, fail-safe relay of original message
- Telegram DM delivery (vm_telegram.py) with per-mailbox routing
- Caller-ID -> name (vm_contacts.py): file / google / carddav backends
- SQLite store (vm_store.py) with content-addressed audio
- FastAPI portal (vm_web.py): PIN login, list/play/delete, per-user settings,
  zero JS, loopback-only behind Apache TLS
- Backfill importer (vm_import.py) for existing spool recordings
- systemd unit, Apache vhost + certbot TLS, install.sh
- Docs: INSTALL, CONFIGURATION, ARCHITECTURE, OPERATIONS, SECURITY, TESTING

Verified end-to-end on mail.txt3.net: 157 historical messages backfilled,
live voicemail -> transcribed -> stored -> visible at https://vm.txt3.net.

.gitignore

@@ -0,0 +1,34 @@
+# Local config with real credentials — never commit these.
+config/telegram.conf
+config/contacts.conf
+*.conf.local
+
+# Runtime data
+*.db
+*.db-wal
+*.db-shm
+audio/
+models/
+*.log
+
+# Test artefacts
+*.eml
+*.wav
+*.mp3
+*.ogg
+preview.html
+ui_preview.html
+tstore.db*
+taudio/
+
+# Python
+__pycache__/
+*.py[cod]
+venv/
+.venv/
+
+# Editor / OS
+.vscode/
+.idea/
+*.swp
+.DS_Store