Adopt verified Route state without redeploying

[squarepots]

Summary

• use persisted state=deploying to distinguish a recovery retry from a fresh pending deployment
• when a retry audit shows in-sync, adopt the verified remote Route into local/observed state without another remote deployment
• keep fresh pending deployment behavior intact, including adoption of validated server-generated payload
• allow remote mutation only from known safe states; drifted or undetermined remote state remains fail-closed

Regression coverage

• pending + in-sync remains a valid initial deployment path
• deploying + in-sync is not permission for another remote mutation
• verified remote state can be committed locally from the durable deploying checkpoint
• the installed user journey remains intact
• existing deployment checkpoint and migration retry coverage remains in place

Version impact

patch — 2.2.2 → 2.2.3

Completes #7 acceptance criterion 3: a local persistence failure after successful remote deployment is recoverable without redeploying blindly.

Closes #7