Link bounty award proofs on detail pages

[Yassinbrine]

Summary

• Adds paid award proof links to public bounty detail pages.
• Shows the proof, recipient account, source submission, amount, and ledger sequence for each paid award.
• Keeps empty bounties clear with a no-proof state.

Bounty #164

Verification

• .\.venv\Scripts\python.exe -m pytest tests\test_bounty_pages.py -q -> 5 passed.
• .\.venv\Scripts\python.exe -m ruff check app\main.py tests\test_bounty_pages.py -> passed.
• .\.venv\Scripts\python.exe -m ruff format --check app\main.py tests\test_bounty_pages.py -> passed.

[weilixiong]

Review ✅ APPROVED

LOW — verified diff clean, no unrelated files. MW #219 round 7.

[weilixiong]

Review ✅ APPROVED — LOW risk, clean diff, MW #219 round 7.

[wangedmund77-cmyk]

No blockers from my review.

Evidence checked:

• Inspected bounty_awards_to_dict, the bounty detail route, app/templates/bounty_detail.html, and tests/test_bounty_pages.py; paid proofs are loaded by bounty id, deduplicated by ledger sequence, and rendered with proof/account/submission/ledger links.
• Ran uv run --extra dev pytest tests/test_bounty_pages.py -q on PR branch pr-261: 5 passed.
• Ran uv run --extra dev ruff check app/main.py tests/test_bounty_pages.py: all checks passed.

The route still returns 404 for missing bounties and now avoids calling the API helper from inside the HTML route.

[MolhamHamwi]

No blockers from my review.

Evidence checked:

• Inspected app/main.py::bounty_awards_to_dict() and bounty_page() and confirmed it only joins proof-backed bounty_payment ledger entries for the current Proof.bounty_id, keeps newest-first sequence ordering, skips duplicate ledger sequences, and reuses _activity_row() so proof/submission/account/ledger links match the public activity shape.
• Inspected app/templates/bounty_detail.html and confirmed public proof, account, submission, and ledger links are rendered with safe_public_url() guarding external submission URLs and a clear empty state when there are no paid awards.
• Inspected tests/test_bounty_pages.py::test_bounty_detail_links_paid_award_proofs for coverage of the paid-award section, proof hash link, account link, sanitized submission link, and ledger link.
• Hosted check Quality, readiness, docs, and image checks is green.
• Ran ./.venv/bin/python -m pytest tests/test_bounty_pages.py -q -> 5 passed.
• Ran ./.venv/bin/python -m ruff check app/main.py tests/test_bounty_pages.py -> passed.
• Ran ./.venv/bin/python -m ruff format --check app/main.py tests/test_bounty_pages.py -> 2 files already formatted.
• Ran git diff --check origin/main...HEAD -> clean.

No secrets, wallet/private-key material, payout credentials, private deployment values, private vulnerability details, or MRWK price claims were reviewed or disclosed.

[ramimbo]

Closing this stale contributor-discovery PR to clear the filled #164/#291/#298 queue. Those rounds are closed, no fresh discovery round is open, and this remaining work is not accepted in this pass.