fix(search): treat a whitespace-only GLOBAL_SEARCH query as no query

[pedrofrxncx]

Bug found while auditing the GLOBAL_SEARCH tool (offset pagination itself is already covered by open PR #5387, which this does not touch or duplicate).

The tool's own docstring promises "Empty string returns the most recently updated resources," but GLOBAL_SEARCH passed input.query straight through to ThreadsStorage.list(), which does if (options?.search) (a truthy check) before applying ilike "%<search>%". A whitespace-only query like " " is truthy, so instead of falling back to "most recent" it silently filters on a literal run of spaces in title — almost always zero results, breaking the documented contract for any client that submits a query the user only whitespace-padded (e.g. a search box blurred after typing then deleting). The same untrimmed pass-through also meant a query like " foo " would fail to match a title of "foo" because the ILIKE pattern included the stray spaces.

Fix: added a small pure normalizeSearchQuery() helper in global-search.ts that trims the query and maps an all-whitespace result to undefined (the same "no filter" value ThreadsStorage.list() already treats as "no search"), and used it in the handler instead of the raw input.query. No change to ThreadsStorage.list() itself, no change to the offset/pagination fields.

Failure scenario before the fix: GLOBAL_SEARCH({ query: " " }) returns { items: [], totalCount: 0 } for an org with recent threads, instead of the documented "most recently updated" listing.

Regression test: apps/api/src/tools/search/global-search.test.ts now covers normalizeSearchQuery directly (pure function, no DB/mocks) for empty string, whitespace-only, padded, and already-trimmed queries.

Reviewer check: bun test apps/api/src/tools/search/global-search.test.ts

Locally ran: bun run fmt, cd apps/api && bunx tsc --noEmit, and the targeted test file above — all green. Full CI covers the rest.

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Summary by cubic

Treats whitespace-only GLOBAL_SEARCH queries as no query, restoring the “most recently updated” fallback. Also trims surrounding spaces so padded queries match as expected.

• Bug Fixes
  • Added normalizeSearchQuery to trim input and map empty/whitespace to undefined; used for the search option in ThreadsStorage.list.
  • Added tests for empty, whitespace-only, padded, and already-trimmed inputs.

^{Written for commit 1be9287. Summary will update on new commits.}