Restore generated analytics API parity

The rebase moved analytics and insight endpoints onto the current Huma-generated API surface, so the checked-in frontend client and read-only mirrors have to expose the same capabilities as SQLite/Postgres before the branch can validate or push cleanly.

DuckDB now mirrors the quality signal columns and implements signal evidence lookups so the shared Store interface continues to compile across backends. The frontend generated client is refreshed so automated scope and signal-session requests use the server's current query shape.

Validation: go fmt ./...; go vet ./...; make test-short; npm --prefix frontend run check; npm --prefix frontend test.

Generated with Codex
Co-authored-by: Codex <codex@openai.com>

Author: mariusvniekerk