pr_runtime: run vitest with its verbose reporter and parse it

[k21993]

Summary

• normalize_test_cmds_for_runtime now gives vitest --reporter=verbose instead of --verbose. Vitest 3-5 reject --verbose with CACError: Unknown option, so no test ran.
• Both JS parsers strip ANSI escape codes, which vitest emits whenever TERM is unset (as in a non-TTY docker exec). In a vitest log, they read only the fully qualified verbose lines and drop the run suffixes ( 12ms, (retry xN), (repeat xN), heap usage, skip note). A project label stays in the name as |unit| file > suite > test, whether or not the output is colored.
• Vitest's default reporter is ignored on purpose. It collapses a fully passing file to one line, so a patch that fixed more than the gold patch would lose its F2P tests (details in pr_runtime can't use vitest repos: --verbose crashes and output doesn't parse #142).
• Jest's padded colored header ( FAIL file) is accepted, so colored jest output parses the same as plain jest output.

Results on a real vitest 5.0.1 bug fix (the div fix from #142, captured with an empty environment):

	Command run	F2P	Agent patch graded
main	npx vitest run --verbose → CACError, no tests	none	task dropped
main parser, even with the right flag	colored verbose output → {}	none	task dropped
this PR	npx vitest run --reporter=verbose	math.test.ts > math > rejects division by zero	1.0, resolved=True

Test plan

• uv run --all-extras pytest -q: 1957 passed, 6 skipped (live-network tests)
• uv run ruff check . and uv run ruff format --check .
• New tests/test_vitest_output.py runs every case against both parsers. Its fixtures are verbatim runner output with local paths shortened to /repo: vitest 5.0.1 before and after the fix, the default reporter, two projects with and without color, vitest 3.2.7, and colored jest 30.5.0.
• 21 of the 23 new tests fail on main (including the normalize_test_cmds_for_runtime case), and all pass with this change.
• The standalone verifier, run with python -I, auto-detects the runner from npx vitest run --reporter=verbose and grades the agent patch at reward 1.0.
• Pathological 200k-character lines (repeated (retry x1), [, digits, >, escape fragments) parse in under 100 ms.
• Manually ran the normalized command on vitest 3.2.7, 4.1.11 and 5.0.1.

Out of scope

• Wrappers such as npm test get no reporter flag, as before (flags would need to go after --), so a vitest suite behind npm test still uses the default reporter.
• Mocha's spec reporter (✔, 1) title) still doesn't parse. I'll file that separately.
• Vitest 2's tree-style verbose output, project names containing spaces with color, and logs that mix jest and vitest runs.
• Tasks generated before this change keep their baked verifier.

Closes #142