Add dynamic city discovery from DOM.RIA sitemap ...

- Implement src/discovery.py to extract city slugs from sitemap.xml.gz
- Use heuristics to filter out regions, districts, metro stations, streets
- Merge sitemap data with homepage navigation links for completeness
- Update config.py to remove hardcoded CITY_SLUGS, use FALLBACK_CITY_NAMES
- Update main.py to auto-discover cities when --city not provided
- Add --discover-cities flag to list all discovered cities and exit
- Tested with Kiev, Lviv, Odessa multi-city dry-run

Co-Authored-By: Claude <noreply@anthropic.com>

Implement MVP DOM.RIA parser with curl_cffi scraping ...

- Add src/ modules: config, session, parser, normalizer, collector, storage, crawler, main
- Implement curl_cffi session with chrome124 impersonation and cookie warmup
- Extract __INITIAL_STATE__ using bracket-counting JSON parser
- Normalize DOM.RIA data into data_collector payload format
- Add SQLite resume storage for deduplication
- Implement rate limiting: 10s between pages/details, 2min pause every 50 pages
- Add CLI entry point with argparse for city/category/operation selection
- Add Dockerfile and requirements.txt
- Update TECH_SPEC.md with v3.0 post-MVP status and empirical data findings
- Update README.md with usage instructions

Co-Authored-By: Claude <noreply@anthropic.com>