feat(e2b): support ACR image resolution and cold-start overrides

[zhongwen666]

closes #1350

Summary

Add optional, deployment-configured ACR region routing and DADI image selection for E2B sandbox creation. Support cold-start resource and readiness-timeout overrides.

Key changes

• Configure resolver plugins through YAML or startup-loaded Nacos settings; support a probe-registry override and fallback behavior.
• Probe accelerated tags in priority order, keep region results local, and share confirmed DADI results through Redis.
• Accept cpuCount, memoryMB, and startup_timeout metadata for cold starts; document their usage in English and Chinese.
• Skip generic registry mirroring for template starts and use template_id directly as the Kubernetes pool fallback.
• Remove fiber_pool_id and change the template image index from unique to non-unique.
• Add focused unit coverage and remove the E2B SDK commands/filesystem/timeout/status integration test file.