Add Algora bounty discovery fallback

[peterxing]

Summary

• add Algora opportunity extraction to runtime-opportunity-scout with the requested API URL tried first
• parse title, URL, real extracted reward_usd, and inferred tech_stack into runtime_jobs payloads
• fall back to public Algora org bounty pages when the API route serves the HTML shell instead of JSON
• add docs/algora-opportunity-scout-proof.md with the observed API response sample and public bounty extraction samples

Verification

• Local parser smoke test against representative Algora page text parsed SCIBASE.AI#13 () and Unsiloed-chunker#34 (,000) correctly.
• Deno is not installed on this host, so I could not run deno check for the Supabase Edge Function.

Closes #4

Payout address for the issue reward: 0x17D7251A8a8d60ab74d7D2B2d20D2a0389871729 on Base USDC.