PrivateGameMatchController has zero test coverage — the #159 429 bug was invisible to CI

[razam-sherwani]

Dependency: READY — start now. No blockers, parallel-safe with everything else. Worth landing before #160 if you want an existing harness for that endpoint's budget tests.

Split out of #159, which is now closed by #168.

PrivateGameMatchController has zero test coverage. Nothing under src/test/ references the class, and every api/v1/game-match string in the suite belongs to GameMatchFileControllerIT / GameMatchFileDownloadIT — a different controller (game-match-file). Re-verified on staging @ d6a6a7e, i.e. after #168 merged.

That gap is why the maxQueuedPerTeam = 0 bug in #159 was invisible to CI: the full suite passed green (118 tests, 0 failures) the whole time the endpoint was 429-ing on first use.

#168 added the right regression guards for the defaulting half (LadderDefaultsTest, AdminLadderControllerIT), but the consuming endpoint is still untested. Two specific paths never execute in any test:

• The cap check, PrivateGameMatchController.java:115 — currentWaitingMatches >= ladder.getMaxQueuedPerTeam() → 429.
• The clamp, :122 — Math.min(maxQueued - currentWaiting, count). This carried a second latent bug behind the first: with the field at 0 it yields 0, so even a relaxed guard would have created zero matches. It deserves its own assertion rather than riding on the entity default.

Suggested coverage

Drive the real POST /api/v1/game-match endpoint (asserting on LadderService alone will not catch a regression here):

1. First match on a fresh ladder succeeds — the direct regression test for Ladder creation silently sets maxQueuedPerTeam to 0, causing immediate 429s #159.
2. Queueing past maxQueuedPerTeam returns 429.
3. count greater than the remaining allowance is clamped to the remainder, and the response reflects the number actually created.
4. allowUserMatches = false is rejected independently of the cap.

Worth noting for whoever picks this up: TestDataFactory.createLadder used to reproduce the production defect exactly — new Ladder() plus nine Glicko fields, never touching maxQueuedPerTeam. It now inherits the correct default from the entity via #168, so the helper needs no change; the missing piece is genuinely the endpoint tests.