Keep command metadata current across ZCode model releases

[bwestlund17]

Summary

• derive a pending ACP session's current model from the first enabled ZCode config entry
• replace release-specific /model and /thought hints with stable argument descriptions
• add regressions covering dynamic pending-session selection and durable command metadata

Problem

The bridge still selected GLM-5.2 for pending sessions and advertised GLM-5.2|GLM-5-Turbo in /model metadata. ZCode 0.16.1 now puts GLM-5.3 first, so the ACP surface drifted as soon as the model catalog changed.

Verification

• npm run build
• npm run typecheck
• npm run lint
• npm test (463 tests)
• source-built package installed and exercised through an isolated Paseo daemon: GLM-5.3 returned 78 core, skill, and plugin commands

[william0wang]

Thanks! Reviewed in a clean worktree — typecheck + 463 tests pass.

Heads-up before you rebase: #47 just merged (squash 2e364dd), and it overlaps with this PR in two places:

1. buildConfigOptions now derives the pending current model from loadAllModels()[0] — same intent as your first change, different implementation. Yours additionally caches loadAllModels() into configuredModels (nice — worth keeping).
2. tests/bugfixes.test.ts / tests/dispatch.test.ts assertions changed shape (Bug 6 thought-vocabulary tests landed).

Your slash-hint de-hardcoding (model id / reasoning effort) is still unique and better than the hardcoded hints — please rebase and keep that part. Conflict resolution should be straightforward; happy to take a final look after.