feat(activities): rank work package activities by relevance

Adds optional query/matchMode to listWorkPackageActivities, ranking the
already-fetched activity list client-side via rankRecords (no extra API
calls). Exposes the same fields on the
openproject_list_work_package_activities tool. When no query is supplied,
every activity is returned exactly as before, and onlyComments continues
to filter independently.

Also fixes a defect in the brief's exact-mode test fixture: the specified
typo query "certificat" is a literal prefix substring of "certificate", so
byte-for-byte exact containment matching (scoreExact in src/search/rank.ts)
finds it regardless of typo tolerance, making the test unable to pass
against a correct implementation. Swapped in "certificatee" (not a
substring of "certificate") to preserve the test's intent without touching
the assertion. Updated one pre-existing test-tools.test.ts call site to
supply matchMode, now required by the extended args type.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/tools.test.ts

@@ -598,6 +598,7 @@ describe("Work Package Tools", () => {
         handleListWorkPackageActivities({
           workPackageId: 999,
           onlyComments: false,
+          matchMode: "fuzzy",
         })
     );