Seam 1 — delivery inferred checkout state from the tree, so whether work survived depended on what the agent happened to do. 019fc444 committed and left a clean tree; 019fc476 had its base advanced to match HEAD; 019fc450 survived only because a phase FAILED to commit and left the tree dirty. Same code, opposite outcomes, decided by the agent. mark_phase_started records the fact at phase launch, before the agent acts, so every one of those states answers identically. The tree checks remain as a second line of defence for pre-existing checkouts. Seam 2 — phase config was accepted, stored and read by nobody. That was `task`: every phase of every mission got identical instructions. The new phase_config registry names the reader for each live key and lists the eight that are declared-but-unimplemented, reporting both at mission creation so an author sees what will not happen. Its CI test found one I had missed: security_hardening.toml sets phase-level mcp_bundles asking for gitea_forge + security_scan, but bundles come from the TEAM template and the phase gets neither. Seam 4 — push_url_for collapsed a failed query, an unbound repo and a missing clone_url into one None, so a database fault was recorded as "nothing to push to" and metadata read `pushed: null, push_error: null` — the same ambiguity commit_error already fixed. Each case now carries its reason into the artifact, and a local git failure during publish is recorded rather than dropped by .ok(). Co-Authored-By: Claude Opus 5 <[email protected]>