docs: add skill-guided ERC-8004 partner flow

[jonathanprozzi]

What changed

• add a recommended skill-guided entry path to the ERC-8004 partner guide
• preserve the complete manual SDK implementation path as the human-readable reference
• document the terminal semantic-planning boundary and phase-specific approval ladder
• make canonical term IDs the primary write and verification contract
• prohibit partner creation of shared predicates, chains, standards, trust models, and OASF taxonomy entries
• clarify pinning API-key storage, live cost handling, and the testnet A2A Agent label caveat
• add the ERC-8004 skill to the AI Skills discovery page
• regenerate the full and medium LLM documentation artifacts

Why

The partner guide and released erc8004-agent-layer skill previously exposed the same integration through separate surfaces without clearly explaining how they fit together. The page now presents one canonical semantic model with two entry paths: skill-guided planning for agents and manual SDK implementation for engineers.

This also incorporates the battle-test findings around deterministic IDs, label ambiguity, missing shared vocabulary, pinning credentials, cost calculations, and approval escalation.

Partner impact

Partners can begin with a deterministic no-write semantic plan, review exact registry IDs and proposed graph structure, and only then move into separately approved protocol phases. Teams that prefer direct SDK implementation retain the full manual flow and use the same registry and safety rules.

Validation

• npm run validate-links
• npm run validate-queries
• npm run validate-sdk-examples
• npm run validate-llms-coverage
• npm run build
• cold no-write tests for guided planning, manual implementation, missing-taxonomy handling, and mainnet approval pressure
• live read-only testnet planner preflight returned semantic_plan_ready for ERC-8004 agent 8453:1380

No pinning or chain writes were performed during validation.