feat(resources): discover -> inspect -> run namespace (list/inspect/estimate/run)

[epanonymous]

Summary

References Bitplanet-L1/cross-eco-internal-docs#299.

Adds the generic agent resources namespace for the merged discover -> inspect -> run rail:

• client.resources.list() / agent.resources.list() unwraps GET /v1/agents/resources/catalog to ResourceInfo[].
• resources.inspect(id) calls GET /v1/agents/resources/catalog/{resource_id}.
• resources.estimate(id, params) calls POST /v1/agents/resources/estimate with { resource_id, params }.
• resources.run(id, params) calls POST /v1/agents/resources/{resource_id}/run.
• Adds shared ResourceInfo, input-schema, estimate, and run-response types.
• Preserves FastAPI detail.error/detail.message in SDK errors for unsupported generic run responses.
• Documents the discover -> inspect -> estimate -> run SDK flow in the README.

Validation

• PASS nice -n 10 npx tsc -b --pretty false
• PASS nice -n 10 npm run build
• PASS nice -n 10 npm test (42 tests)