Major refactor: Typer CLI, comprehensive tests, and CI improvements

Major refactor: Typer CLI, comprehensive tests, and CI improvements

- Migrate CLI to Typer for tab completion and better argument handling
- Split tree.py into modular tree/ package (core, records, elements, utils)
- Add comprehensive test suite with merge idempotency, session caching, etc.
- Add offline test fixtures via git submodule (res/testdata)
- Set up GitHub Actions CI with Coveralls integration
- Add git-sqlite-filter for reproducible SQLite fixture handling
- Improve merge deduplication for names, facts, notes, and sources
- Fix session cookie/caching and rate limiting
- Add Makefile for common dev tasks

Modernizes the tool with a new CLI, faster and safer networking, and a refactored tree/session architecture to improve reliability and performance. Adds CI and tests, and consolidates packaging for easier development.

- **New Features**
  - New CLI with exclude list and distance options; UTF‑8-safe output.
  - HTTP caching (requests-cache), optional cache-control, and request rate limiting; persistent cookie cache.
  - Offline mode to use cached data without logging in.
  - Place enrichment via Geonames/geocoder with structured Place objects.
  - Clear GUI Tkinter error; first‑run license prompt stored locally.
  - Immigration fact mapping and contributor attribution from change logs.

- **Refactors**
  - New GMASession with cached session; switched to FS IDs; tree split into elements/records; legacy getmyancestors.py removed; entry points updated.
  - Added unit/integration tests and GitHub Actions (Linux/macOS/Windows); Makefile targets; linting/formatting gates.
  - Dependencies consolidated in pyproject; added requests-cache, requests-ratelimiter, geocoder; removed requirements.txt.
  - Fixed merge duplication; idempotent merges via set-based dedup in mergemyanc.