Fix Lopu all-branch Graphify and promisor handling

[lopugit]

Summary

• pin the complete generated graphify-out/ subtree to the primary base after every synthetic PR merge
• recover partial-clone promisor failures with one exact, unfiltered refetch and retry
• keep Graphify conflicts from excluding real source changes or ballooning the all branch
• refresh the content-addressed control-plane graph snapshots

Validation

• node .github/scripts/build-all-branch.mjs --self-test
• node .github/scripts/workflow-control-plane-contract.mjs --self-test
• node .github/scripts/resolve-pr-conflicts-routing-contract.mjs --self-test
• node .github/scripts/stage-graphify-snapshots.mjs --self-test
• node --check .github/scripts/build-all-branch.mjs
• git diff --check
• live blobless dry run against all 48 open PRs with ALL_PUSH=0: 47/47 eligible PRs merged, only PR ci: notarize Commander Developer ID releases #400 skipped because its base is the protected github-actions control plane rather than a product-stack head
• final synthetic graphify-out tree exactly matched origin/develop:graphify-out