feat(ecosystem): Add payable.link to ecosystem

[ilkaydnc]

Description

Add payable.link to the x402 ecosystem page.

payable.link is a digital file marketplace powered by x402. Sellers can upload any file (up to 1GB), set a USDC price, and share a link. Buyers pay with crypto on Base and get instant download access. The platform supports both human users and AI agents via the x402 protocol and EIP-191 authentication.

• Category: Services/Endpoints
• • Website: https://payable.link
• • Documentation: https://payable.link/llms-full.txt

Tests

N/A — ecosystem listing only (metadata.json + logo).

Checklist

• I have formatted and linted my code
• - [x] All new and existing tests pass
• - [ ] My commits are signed (required for merge)
• - [ ] I added a changelog fragment for user-facing changes (docs-only changes can skip)

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1

[vercel]

@ilkaydnc is attempting to deploy a commit to the Coinbase Team on Vercel.

A member of the Team first needs to authorize it.