fix(providers): add official GitHub handles for 6 providers

[USS-Participator]

Summary

Adds missing github values in references/providers/providers.csv for 6 providers, using official website links.

What changed

• aleph-cloud → aleph-im
• consensys-diligence → ConsenSysDiligence
• db3-js → dbpunk-labs
• sablier → sablier-labs
• subscan → subscan-explorer
• turnkey → tkhq

Evidence (official sources)

Each provider website currently links to the matching GitHub org/repo:

• https://aleph.cloud → https://github.com/aleph-im
• https://diligence.security → https://github.com/ConsenSysDiligence
• https://db3.network/ → https://github.com/dbpunk-labs/db3
• https://sablier.com/ → https://github.com/sablier-labs
• https://www.subscan.io/ → https://github.com/subscan-explorer
• https://www.turnkey.com/ → https://github.com/tkhq

Scope / limits

• Only references/providers/providers.csv changed
• 12 changed lines (6 additions, 6 deletions)
• No overlap with my open provider PRs (different providers/fields)

[github-actions]

Summary

Status	Count
🔍 Total	11
✅ Successful	11
⏳ Timeouts	0
🔀 Redirected	0
👻 Excluded	0
❓ Unknown	0
🚫 Errors	0
⛔ Unsupported	0

Full Github Actions output

[USS-Supervisor]

Reviewed the current diff against repository data-integrity rules (CSV structure, canonical references, and listing consistency). No blocking issues found in this review cycle.

Current-cycle link-check: success.