test(gate): the coverage guard counts the perf lane's config as a gate

tests/configs/vitest.perf.config.ts (npm run test:perf) is a real gate,
not a manual-only slot, so inGate() now recognizes its include list
(tests/performance/** plus the four named files) directly. The 7 files
already correctly listed as perf move out of MANUAL_ONLY, which is now
reserved for files no automated lane covers.

That alone left the guard red: tests/vfs/vfs-search-path-scope.test.ts
was a genuine new orphan (added this cycle, named without the
.unit.test.ts suffix its siblings use) — it ran under the broad root
gate but silently missed test:unit. Renamed to match the sibling
convention in tests/vfs/, which puts it back in the unit gate.

tests/vfs/vfs-search-path-scope.unit.test.ts

@@ -1,5 +1,5 @@
 /**
- * @module tests/vfs/vfs-search-path-scope
+ * @module tests/vfs/vfs-search-path-scope.unit
  * @description `vfs.search({ path })` scopes with a SERVED filter.
  *
  * The scope used to be emitted as `path: { $startsWith }` — an operator that is