Remove managed SRT and prepare CLI 0.10.11

[ZhiXiao-Lin]

Summary

• remove the managed Anthropic SRT bootstrap, probe, packaging, and updater paths
• replace it with a shared Rust host-command guardrail for TUI, Web, and non-interactive execution
• pin both TUI and Web backend integration to published a3s-code-core 6.5.1
• prepare the first SRT-free CLI release as 0.10.11

Validation

• release-state and formatting checks passed
• Clippy passed with all targets and published dependencies
• full cargo test --all-targets --locked passed against crates.io-only A3S dependencies
• focused TUI/Web/host guardrail tests: 26 passed
• Web frontend: formatting, lint, typecheck, 1,228 tests, production build passed
• real Code Core context-tool suite: 4/4 passed with gpt-5.6-terra
• real CLI host-guardrail process test: 5/5 scenarios passed with codex/gpt-5.6-terra

Release dependency

a3s-code-core 6.5.1, Node packages, Python bootstrap, native wheels, and GitHub Release are published and verified.