Improve CLI sandbox startup and transport reliability

[yifanxuaaa]

Summary

• reduce one-shot CLI and sandbox startup overhead across the runtime, layer stack, observability, and gateway paths
• use local IPC for gateway CLI transport while preserving TCP endpoint compatibility
• harden request identity, workspace writes, namespace completion, resource sampling, and daemon archive behavior encountered during EXP1
• merge the latest documentation-only origin/main update without rewriting the frozen experiment commits

Validation

• focused changed-crate and CLI transport tests passed during the frozen campaign
• real named-pipe request/response and concurrency-5 qualification passed
• final EXP1 v1.1 campaign completed 1,900 reportable measured batches and 5,610 requests with zero classified failures

Notes

• this PR is intentionally draft-only; the experiment code must remain off main for now
• annotated freeze tag paper-v1.1-freeze points to product commit 5c48dae10847fb9e46ba2bea7675bcf2f5a6f4c8