[Data-11] Cache Attach fix

[Zhimin-arya]

Merge Checklist

1. set createDbFileIfMissing=true when attach HANA to duckdb cache, set the cache name as ${database_code}_cache.db
2. Update search_embedding flow for hana and create_cachedb_hana_plugin with new cache name
3. Update hybrid search on hana accordingly

Screen.Recording.2026-07-02.at.15.15.29.mov

• Automated Tests (Jasmine integration tests, Unit tests, and/or Performance tests)
• Updated Manual tests / Demo Config
• Documentation (Application guide, Admin guide, Markdown, Readme and/or Wiki)
• Verified that local development environment is working with latest changes (integrated with latest develop branch)
• following best practices in code review doc

[Copilot]

Pull request overview

This PR updates Trex server startup cache attachment so cache databases can be attached even when the underlying .db file doesn’t exist yet (allowing DuckDB to create it on first attach), addressing cache attach failures at startup.

Changes:

• Remove the previous startup logic that enumerated HANA datasets and attempted to attach their caches explicitly.
• Pass createDbFileIfMissing: true when attaching portal-derived cache_id databases during startup.

[csafreen]

why is _cache added for HANA datasets?

[Zhimin-arya]

Because if cache_id == database_code trex routes to directly HANA connection, but in search_embedding we need hana cache in duckdb cache. So append _cache makes trex to connect cache instead.