feat: harden Algora bounty discovery parsing

[wangedmund77-cmyk]

Summary

• Tries the issue-specified Algora endpoint first and keeps a console fallback without inserting rows from non-JSON/failed responses.
• Normalizes Algora tech_stack from common API fields and writes it into runtime_jobs.payload.
• Deduplicates Algora candidates by URL before the existing SHA-1 task id insertion path.
• Adds docs/algora-opportunity-scout-proof.md with current endpoint probes and accepted JSON shape.

Bounty

• Addresses 🔍 [Agent Task] Add Algora bounty discovery to runtime-opportunity-scout #4 ($3 USDC).

Verification

• curl -L -H "Accept: application/json" https://algora.io/api/bounties?status=open&limit=50 currently returns {"errors":{"detail":"Not Acceptable"}}; documented in proof file.
• npm run typecheck not run successfully because dependencies are not installed in this environment (tsc: command not found).