[ancongui]

An implementation can fail after the agent has changed files and every model response has already been consumed. That source previously had no supported checkpoint path. This change lets the authenticated project owner preserve it through the existing Git delivery queue, with an unverified commit and draft PR. The failed run, graph hold, task attempt and consumed responses remain intact.

The server checks the complete recorded completion chain, the latest stored source frontier, current Git consent, actor permissions, ownership and settled command/tool effects. Only supported read-only source calls may follow that frontier. It validates delivery summaries and draft references against their native receipts before each Git phase. Unknown effects remain held; historical runtime contracts are rejected.

The API, Python client and guide cover candidate review and explicit source-only consent. Current journal custody bounds remain 10,000 records/16 MiB; this PR does not remove enterprise capacity limits or authorize graph restoration.

Validation:

• 42 focused tests, 137 earlier Git compatibility cases, mypy (308 modules), Ruff and formatting.
• Seven fresh PostgreSQL cases, including real bare-Git push with controlled draft-provider HTTP, late source/authority/ownership changes, receipt rollback and unknown-commit handling; complete cleanup verified.
• Strict documentation build and extracted wheel smoke with sockets denied.
• An actual local factory run created a GitHub App commit and draft PR from preserved CRM changes. Product verification on that checkpoint is still pending.