Fix: finish the per-file vitest timeout-budget audit under tests/integration

[AmaadMartin]

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Link to Issue or Description of Change

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2. Or, if no issue exists, describe the change:

Problem: vitest.config.ts sets hookTimeout: 120000 and testTimeout: 60000 for the integration project, but a per-file argument overrides that value in both directions. Several integration files predate the config and still pass their own budget, so they now silently lower the limit: an npm install hook capped at 40s, and a server-start hook capped at 20s. Those caps also sit at or below the 60s start watchdog in tests/integration/test_api_server.ts, so vitest kills the hook before the server can report its captured stdout.

Solution: I deleted every per-file budget under tests/integration/ that restates or undercuts the project default, so vitest.config.ts is the single source of truth. Two overrides survive because they have a stated reason: the 20s per-test budget in build_setup_test.ts, and the 40s budget in tools/run_skill_script_tool_test.ts that must exceed UnsafeLocalCodeExecutor's own 30s timeout. I renamed the a2a TEST_TIMEOUT constants to SERVER_START_TIMEOUT_MS, because they now only feed the server's start watchdog. I also moved the measurement that justifies 120000 into the vitest.config.ts doc comment, since it used to live in a comment this change deletes.

Audit result:

File	Was	Now
a2a/basic/a2a_agent_test.ts	beforeAll 60s	inherits 120s
a2a/input_required/input_required_test.ts	beforeAll 60s	inherits 120s; constant renamed
a2a/stream/stream_test.ts	beforeAll 60s	inherits 120s; constant renamed
adk_web/webui_test.ts	beforeAll 20s, suite 20s	inherits 120s / 60s
agent_loader/agent_dirname_test.ts	hooks and test 40s	inherits; constant deleted
build_setup/build_setup_test.ts	hooks 120s, tests 20s	hooks inherit; 20s kept with a reason
skills/script_js/agent_test.ts	hook and test 60s	inherits; constant deleted
tools/run_skill_script_tool_test.ts	tests 40s	unchanged, on purpose

Duplicate check: I listed all 652 open PRs on the fork and read every plausibly adjacent diff. #478 and #405 attempt the same audit but are superseded. #405 re-lands the vitest.config.ts values that #548 already merged, and #478 deletes the run_skill_script_tool_test.ts override this change deliberately keeps. #506 owns app_loader_test.ts and removes the same hook budgets there. This branch already carried those hunks, so I left them as they are.

Deviation: app_loader_test.ts keeps a 40s per-test budget under the 60s default with no concrete reason. That file belongs to #506, so editing it here would only create a conflict. Every other file in tests/integration/ now satisfies the rule.

Note on the diff size: removing the third argument from an it(name, fn, timeout) call lets Prettier hug the call, which re-indents the test body. That is why skills/script_js/agent_test.ts shows more changed lines than it has changed behaviour.

Testing Plan

Please describe the tests that you ran to verify your changes.

Unit Tests:

• I have added or updated unit tests for my change. No new test is possible here: the change only deletes test-harness configuration and adds no production code. The changed files are themselves the tests.
• All unit tests pass locally.

Commands run on the pushed commit:

npm run build                                                            # pass
npx vitest run --project integration tests/integration/a2a tests/integration/adk_web
                                                                         # 4 files, 8 tests pass
npx vitest run --project integration tests/integration/agent_loader      # 3 tests pass
npx vitest run --project integration tests/integration/skills/script_js  # 1 test passes
npx vitest run --project integration tests/integration/build_setup \
    tests/integration/tools/run_skill_script_tool_test.ts                # pass
npm run lint                                                             # clean
npm run format:check                                                     # clean

Proof the change is load-bearing. I restored the old 40s hook budget in agent_loader/agent_dirname_test.ts and re-ran the suite. It fails:

Error: Hook timed out in 40000ms.
 Test Files  1 failed (1)
      Tests  3 skipped (3)

With the budget removed, the same suite passes in 228.7s for three fixtures whose tests take 4.7-4.9s each, so the install and teardown hooks account for about 76s per fixture. That is over the old 40s cap and inside the 120s project budget. skills/script_js/agent_test.ts measures the same way: 94.0s for the file against a 6.6s test, so about 87s of hook time under a cap that used to be 60s.

Known pre-existing failure: npx tsc --noEmit reports 280 errors. The identical 280 errors are present on main, all in core/test/**, and none in a file this change touches. CI does not run ts:check, so this is unrelated breakage and I did not fix it.

Manual End-to-End (E2E) Tests:

1. Run npm run build.
2. Run npx vitest run --project integration tests/integration/agent_loader on a cold npm cache. The install hook now has 120s instead of 40s.
3. To see the second failure mode, break a fixture agent so the CLI never prints its ready line. adk_web/webui_test.ts now reports the server's own Timeout waiting for cli to start. and its captured stdout, instead of a bare Hook timed out in 20000ms.

Checklist

• I have read the CONTRIBUTING.md document.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.

[AmaadMartin]

Rebase and narrow. Four of the eight files overlap #405, and build_setup_test.ts is byte-identical to it. The new coverage is the three a2a suites and webui_test.ts, and the note about the 60s server watchdog is worth keeping. Please cut this to those four files.