(janitor/test-prune): Remove tautological/duplicate tests in utils.test.ts

[kilo-code-bot]

Summary

Removes three low-value tests from apps/web/src/lib/utils.test.ts that
cannot detect a plausible production regression and add ongoing
maintenance cost without protecting any additional behavior. No
production code changed.

Removed tests and surviving coverage

1. assertNotNullish — "should properly narrow types (compile-time test)"

• Claimed to test: TypeScript type narrowing after assertNotNullish.
• Why it's safe to remove: The test's own name/comment says it's a
  "compile-time test." If the type declaration on assertNotNullish
  were wrong, tsc/pnpm typecheck would fail — not this test. At
  runtime, the test only calls assertNotNullish with non-null values
  (no-throw path) and then calls built-in String.toUpperCase/
  Number.toFixed, which exercise no additional branch of
  assertNotNullish.
• Surviving coverage: should not throw when value is not null or undefined (non-null/undefined inputs, no-throw path) and should throw a custom error message when provided (null/undefined inputs,
  throw path and custom message) in the same describe('assertNotNull')
  block fully cover the function's only two runtime branches.
• Regression this could not detect: None beyond what the two
  neighboring tests already detect — a broken narrowing type
  declaration is caught by typecheck, not by this test.

2. toNonNullish — "should properly narrow return type (compile-time test)"

• Same pattern as (1), for the sibling function toNonNullish (which
  simply calls assertNotNullish and returns the value).
• Surviving coverage: should return the value when it is not null or undefined and should throw an error when value is null or undefined in describe('requireNotNull') cover both runtime
  branches (return value, throw with default/custom message).

3. parseResultJsonWithZodSchema — "should preserve console.log behavior on JSON parse error"

• Claimed to test: Console logging behavior on a JSON parse
  failure — but the test body never references console.log or
  spies on it.
• Why it's safe to remove: It is an exact duplicate of the test
  immediately above it — same createMockResponse(400, 'Bad Request', null, true) setup, same rejects.toThrow('Failed to fetch data: Bad Request') assertion — minus that test's jsonMock call-count
  check. It tests strictly less than its neighbor while claiming to
  test something (console logging) that isn't asserted at all.
• Surviving coverage: should handle error response when JSON parsing fails (immediately preceding test) exercises the identical
  code path with an equal-or-stronger assertion (adds the
  jsonMock call-count check).
• Regression this could not detect: None — any regression in the
  JSON-parse-failure path is already caught by the preceding test with
  an equal or stronger assertion.

Verification

• apps/web tests require a reachable PostgreSQL instance via
  setupFilesAfterEnv (workerSetup.ts), which is unavailable in this
  sandbox (no docker/postgres). Ran a full repo-wide tsc --noEmit
  attempt, but it exceeded the sandbox's memory/time limits and could
  not complete.
• Ran oxlint --config .oxlintrc.json apps/web/src/lib/utils.test.ts
  directly on the changed file: 0 warnings, 0 errors.
• Ran oxfmt on the changed file (repo formatter) — no formatting
  drift beyond the deletions.
• Manually re-read apps/web/src/lib/utils.ts (assertNotNullish,
  toNonNullish, parseResultJsonWithZodSchema) to confirm every
  runtime branch removed tests exercised remains covered by a
  surviving test with an equal or stronger assertion.
• git diff --check — no whitespace issues.

No production code, other test files, or unrelated tests were touched.