Preserve integration replay ancestry and scoped derived provenance repair

[Yehonal]

Change

• Classify old-parent history only through an exact two-parent reconciliation proof, and require product history to belong to a selected stack or another established provenance source.
• Recognize historical commits carried by a validated reconciliation and exact, already delivered superseded stack history.
• Allow Agentwheel to repair stale derived-path provenance one scoped path at a time, while requiring the stale set to shrink.
• Release as 0.45.2.

Verification

• Real ten-stack, 46-commit replay regression with nonempty product commits and ancestry/tree assertions: passed locally.
• Targeted reconciliation, superseded history, exact merge, unselected-stack negative, and incremental provenance tests: passed locally.
• Read-only integration history and reconciliation-proof probe on the affected deployment repository: passed.
• syncwheel validate: zero errors (existing historical unmapped-commit warning).
• git diff --check and generated version check: passed.
• The full local suite exceeded this host's parallel fixture capacity; affected tests pass when run separately. CI shards run on separate workers and must pass before merge.

Rollout

Upgrade the installed uv tool after merge, then verify its version and the target repository diagnostics.