Add first-class site aliases

[janhelcl]

Summary

• add a site_aliases table with normalized aliases and uniqueness per site
• search canonical names and aliases through the same deterministic ranking engine
• keep public REST/MCP output canonical (site_id, name) with no MCP schema change
• seed Bassano/Monte Grappa and Meduno/Valinis aliases
• reload aliases during FORCE_INITIAL_DATA_LOAD
• add regression tests for ranking, deduplication, fuzzy alias matching, and DB integration

Ranking

Within each match class canonical names outrank aliases:

1. exact canonical
2. exact alias
3. prefix canonical
4. prefix alias
5. substring canonical
6. substring alias
7. fuzzy canonical
8. fuzzy alias

An exact alias can therefore beat a weaker canonical prefix/substring match.

Deployment

Migration seeds existing populated databases using INSERT ... SELECT. Fresh/full reloads use app/data/site_aliases.csv, so aliases survive site replacement.