Spec Kitty

Mission Run: Coordination Topology Stabilization

Fix eight confirmed defects blocking reliable use of the coordination topology, including self-defeating accept gates, index leakage, silent failure modes, and a missing retrospective trigger.

The coordination branch topology (introduced in 3.x) separates write paths onto a coordination branch while read paths and gates still anchor on the primary checkout. This mismatch has produced eight confirmed defects (issues #1164, #1878, #1883–#1888) that together prevent operators from completing a mission lifecycle without manual workarounds: a non-convergent accept gate, a coordination-blind setup-plan gate, 26 leaked .worktrees/ paths tracked on origin/main, a silent exit-0 stub for mission-not-found, stale-assertion false positives, unconsumed ownership warnings, and a retrospective that never fires on the dominant merge path. Fixing these restores the invariant that the spec-kitty toolchain is self-consistent and operator-trustworthy across the coordination topology.