feat: add bounded provider evidence probes

[minglong51]

Summary

• add bounded, fail-closed Claude, Codex, and Kimi probe drivers over the existing private capture collectors
• bind each probe to reviewed executable bytes and bind the generated capability matrix to the canonical executable manifest
• run provider-probe contracts in CI while keeping raw frames, prompts, transcripts, credentials, paths, and identifiers outside git

Evidence status

Controlled live attempts produced no eligible observed capability rows. The committed 24-cell matrix therefore remains synthetic, all-unknown, non-authoritative, and attach_only_unknown; private run artifacts are not published.

Verification

• PYTHONDONTWRITEBYTECODE=1 python3 -m unittest -v tests.test_profiles tests.test_release tests.test_provider_evidence tests.test_provider_probe — 122/122 passed
• PYTHONDONTWRITEBYTECODE=1 python3 scripts/provider_evidence.py --check — 24/24 cells passed
• independent security re-review — no blockers
• exact public-repo redaction scan of origin/main...HEAD — zero findings

Follow-up to #21.