feat(client): generate complete protocol client

[kitlangton]

Summary

• generate Promise and Effect clients from every authoritative Server HttpApi group
• define stable public group and endpoint names for the expanded client surface
• extend codegen for explicit endpoint names, buffered binary responses, name-discriminated errors, and safe schema reference expansion
• preserve the zero-Effect Promise entrypoint and full Server/Protocol contract identity checks

Verification

• bun typecheck in packages/httpapi-codegen
• bun run test -- generate.test.ts in packages/httpapi-codegen (57 passed)
• bun typecheck in packages/client
• bun run test in packages/client (10 passed)
• bun run check:generated in packages/client
• file-scoped Prettier and oxlint checks
• repository push hook: full monorepo typecheck (29 tasks passed)

This PR only expands the generated client and its generator support. It does not migrate the TUI or remove the legacy SDK client.