Promote durable pending action approval contracts

[chubes4]

Summary

• Promotes pending action records to a durable audit shape with workspace, agent, creator, lifecycle status, timestamps, resolver, and resolution result/error metadata.
• Expands store, resolver, and handler contracts to cover list/summary/expire/delete audit operations plus handler-level resolution permission checks.
• Documents the approval boundary and updates smoke coverage for the durable contract surface.

Closes #59.

Tests

• composer test
• homeboy test
• homeboy lint

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (GPT-5.5)
• Used for: Drafted the durable approval contract updates, tests, docs, and PR description; Chris remains responsible for review and merge.