Add Junct action provider for DeFi MCP server access

[junct-bot]

Summary

Adds a junct action provider that enables AgentKit agents to access DeFi data through Junct-hosted MCP servers.

15 protocols: Binance, Aave, Chainlink, Curve, CoinGecko, DefiLlama, ENS, Lido, Compound, EigenLayer, Jupiter, Stargate, Beefy, Maker, Blockscout

3 actions:

• list_junct_servers — discover available servers
• list_junct_tools — list tools on a server
• call_junct_tool — invoke a tool

Uses MCP JSON-RPC over HTTP (same fetch() pattern as other providers). Zero new dependencies. Network-agnostic.

Test plan

• pnpm run build passes
• pnpm run lint passes
• Unit tests pass

[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 1 Sum 2

[junct-bot]

Junct is the agent-readiness layer for the crypto stack — deterministic MCP servers, 1:1 spec coverage, no AI generation, fully auditable.
Checking in on this PR. The integration connects AgentKit agents to Junct's hosted DeFi server registry -Pyth, DeFiLlama, CoinGecko, Chainlink, GMX, Synthetix, Curve, Binance, EigenLayer, Maker, ENS, Euler, Stargate, Blockscout, Beefy, Jupiter and Lido, all live at *.mcp.junct.dev. No auth, no API key, free to use. Happy to make any changes needed for review.