[codex] Fix Kiro ACP image attachment errors

[declancowen]

Summary

• Preserve ACP JSON-RPC error data so Kiro image failures surface as provider request errors instead of Effect decode defects.
• Add ACP image prompt capability checks and Kiro MIME allowlist support for PNG/JPEG/GIF/WebP.
• Address review findings for ACP request ID aliasing, shell env probing, desktop update recovery, release workflow refs, compact send rendering, and credentialed browser CORS.

Validation

• bun run test src/client.test.ts src/protocol.test.ts from packages/effect-acp
• bun run test src/provider/acp/StandardAcpAdapter.test.ts from apps/server
• bun run --cwd apps/server test src/http.test.ts src/server.test.ts
• bun fmt
• bun lint
• bun typecheck
• bun run test

Review

• Codex review on head 7d1ec6d2 completed with no major issues.