Extends the existing dispatch_allow flag (which already injects .dispatch-allow,
#43/#51/#53) to also append owner/name to mathias/dispatch's git-tracked
dispatch-repos.txt (dispatch#19) — the second of the two required dispatch
gates. Being listed there is necessary but not sufficient on its own (the repo
still needs its own .dispatch-allow marker) — both are applied independently,
neither implies the other, matching dispatch#3's structural trust-zone design
where both must say yes.
Idempotent: a repo already listed (e.g. dispatch_allow re-requested on resume)
is a no-op, not a duplicate line. Failure is reported in its own
dispatch_allowlist_failure field, distinct from partial_failure (substitution)
and dispatch_allow_failure (the marker file) — the three gates can each fail
independently, never conflated (same principle as #51).
The allowlist owner/repo/path/branch are hardcoded to match mathias/dispatch's
own DISPATCH_ALLOWLIST_* env defaults, confirmed unoverridden in the live
CronJob (2026-07-06) before implementing.
Tests: fresh registration (existing entries preserved, not clobbered),
already-listed no-op (zero writes), allowlist-write failure as a distinct
field, dispatch_allow=false never touches the file.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>