ci(codex): refresh extension timing calibration (#154243)

ci(codex): refresh extension timing calibration (#154243)

Replace pre-fixture Codex test estimates with wrapper timings from three successful PR runs after shared database-worker fixture reuse. Preserve ordinary serial/non-isolated execution, native isolated forks, worker budgets, and both 12-file process caps.

Refresh ordinary Codex to 2.490 seconds/file, the database-worker aggregate to 7.599, and the native app-server floor to 17.31. Assert the selected native child's own measured cost and document calibration units and source runs. Both requested replay sets preserve all 124 envelopes while reducing extension rows from 50 to 48 and the Codex prediction from 609 to 291 seconds.

Validation: 2,673 planner/config tests; scoped changed-file, type-aware lint, formatting, MDX and whitespace checks; P2 review clean. Exact-head CI run 35554354798 passed on its first attempt. These are calibrated estimates, not a claim of lower measured CI wall time. Parallel scheduling and its controlled performance investigation are isolated in draft #154319.

Refs #153539, #154057.