Generated command and skill version drift has no compatibility diagnostic

Observed while running the #2658 mission (TF-024).

## Reproduction

1. Install a current Spec Kitty CLI and generate/project its command skills.
2. Invoke a slash-command payload stamped with an older `spec-kitty-command-version` (observed: 3.1.2a3) while the projected task skill comes from a newer CLI (observed: 3.2.5+).
3. Observe no diagnostic explaining compatibility, instruction precedence, or whether regeneration is required.

## Expected

At invocation or context resolution, emit a machine-readable version compatibility decision: compatible, regenerate, or unsupported, including which instruction source is authoritative.

Start at command invocation and context resolution, reproducing the mismatch between the observed 3.1.2a3 command payload and 3.2.5+ projected task skill. Trace how instruction sources are selected, then define and verify a machine-readable compatible, regenerate, or unsupported decision that identifies the authoritative source.

Written by the indexing model from the issue text.