Mission Run Overview
Mission Run: Post-Merge Write Mode and Authoring Finish
Let evidence writes succeed after a mission merges, and finish the deterministic authoring commands PR #3076 left partial.
PR #3076 shipped the write-side placement seam but deferred the post-merge write mode (evidence writes fail against a deleted target branch, #3033) and left two authoring commands half-built (#2318 negative-invariant handling, #1738 URL-form issue references). This mission lands the deferred P0 write-mode fix and the remaining authoring finish-work so the write-side seam is complete.