Factory sync: .factory/MAINTENANCE.md

.factory/MAINTENANCE.md

@@ -42,8 +42,8 @@ reply is the report.
    to the version it prints.
 2. Extract the Skills to `.kiro/skills/`:
    - sbt: `extractSkillsJars` through the `sbta` server's `sbt-task` tool, or
-     `./sbta extractSkillsJars`. After `build.sbt` changes, sbt reloads; if the next call reports a
-     lost connection, run it again.
+     `./sbta extractSkillsJars`. Run `reload` first after editing the pin, or it extracts the old
+     version; check the version in its output. If a call reports a lost connection, run it again.
    - Maven: `./mvnw -q skillsjars:extract`
    - Gradle: `./gradlew extractSkillsJars`
 
@@ -54,7 +54,7 @@ reply is the report.
    for a version released in the last day usually means the same thing: the mirror doesn't have it
    yet, so the build fell back to Maven Central (check with `curl -s -o /dev/null -w '%{http_code}'
    https://maven-central.storage-download.googleapis.com/maven2/<path>`; 404 means not mirrored). Pin
-   the newest version the mirror has and continue. For any other download error (for example a 429
+   the newest version the mirror has and continue, unless the repo's code already needs the unmirrored version (the build at the default branch pins it and fails to compile against the older one): then the bump can't be validated, so follow the stop rule at the top and report which artifact was missing. For any other download error (for example a 429
    for an older artifact, or a proxy 403), stop and report it instead of changing resolvers.
 3. Read `.kiro/skills/*zen-of-projects*/SKILL.md` and follow its "Maintenance Routine" section, using
    `AGENTS.md` for this project's commands and documented exceptions. While an unreleased version of