v0.2.25

fix(control): validate activation PR author identity (#103)

## Correction

Normal activation PR #102 failed before the merge API call because the active runtime compares head.user (the source repository owner) to the Server App. Validate the top-level PR author ID/login/type and retain exact head, canonical branch, repository identities and protected base. The regression uses the observed GitHub shape and rejects 13 identity/state substitutions plus the swapped-author impostor. No workflow, token or policy exceptions.

## Evidence

Signed source ae9bd8990e7d11e77e054da0674a2de6710308b6; parent cf98fd0d399b5951f8f8c4a6e06a48842d8b098f. Formatting, 302 Rust execution tests, documentation-test stage (zero tests), Clippy and diff checks passed. Two existing tests remain ignored. Independent source and prose reviews completed. Required CI remains the next gate. Active generation-one descriptor unchanged.

## Promotion limits

The immutable v0.2.23 runtime cannot acquire this correction from main. Source merge, exact-main scratch prepare/verify and normal v0.2.25 publication/proposal can use the normal controller. Activation needs a separately reviewed fixed recovery authority with new explicit approval; bootstrap remains retired. No distribution until activation and the full scratch caller migration succeed.