fix(store): honor profile in local search

[upsetbit]

Summary

Fixes #290.

Local search now honors the --profile filter and returns the session profile in JSON hits.

What changed

• Added s.profile = ? to the local search filter path when SessionFilter.Profile is set.
• Selected and scanned sessions.profile into SearchHit.Session.Profile.
• Added a regression test for work vs default profile search hits.

Validation

• go test ./internal/store -run 'TestSearchFilterByProfileAndReturnsProfile|TestSearch' -count=1
• go test ./internal/store/... -race
• go test ./internal/cli/... -race
• go build -o ./bin/prosa ./cmd/prosa