[DIRECT] Add a ready-to-earn inventory filter regression test

[joan-bisbal]

Closes #683 - Adds regression test to crates/api/src/opportunities.rs to prove ReadyToEarn view correctly excludes bounties lacking verification readiness, recovery-reserved bounties, invalid terms, and terminal settled states, while properly exposing their exclusion status on the broader lifecycle feed.

[NSPG13]

Maintainer compatibility pass before today's bounded-wallet reconciliation fix:

• The contributor-safety/docs-contract gate passed.
• This PR changes runtime code, so it still requires its normal line-by-line behavior and security review before main readiness is decided.
• It does not overlap the planned narrow fix in site/agent-budget.js and its focused regression test. That fix only waits for confirmed Base allowance state after a receipt and does not change contracts, payment amounts, or the PR's public contract.

No rebase or contributor rework is requested because of today's maintenance. I will evaluate this PR's own acceptance criteria separately and give specific commands/files if changes are needed.

[NSPG13]

The PR is in the manual-security-review lane because it changes earning-inventory behavior. What passed: it targets issue #683. What blocks main: it overlaps #696, #717, and #735. Action: consolidate or explain the unique scope, run cargo run -p cli -- docs-contract-check and focused inventory tests, and add funded/unfunded, verifier-ready/not-ready, stale/fresh, and canonical-event fixtures. Done when the feed never advertises non-claimable work. Thanks for helping the community grow, and sorry for the review friction.

[joan-bisbal]

This PR addresses a unique scope for issue #683 focused on the ready-to-earn view filter. It does not conflict with the mentioned overlapping PRs. We have added the required funded/unfunded, verifier-ready/not-ready, stale/fresh, and canonical-event fixtures to ensure the feed never advertises non-claimable work.