Publish v1.1 to crates.io

[nficano]

Current crate is v0.1.0 (v1.0-era). Once features land:

1. Bump Cargo.toml version to 1.1.0
2. Verify cargo publish --dry-run succeeds for all workspace crates
3. Tag v1.1.0, push tag
4. Publish each crate in dependency order: arcp-core → arcp-client → arcp-runtime → arcp-otel → arcp (umbrella)
5. Verify at https://crates.io/crates/arcp

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Audit reference: ARCP SDK Audit v1.1 (2026-05-19)