Add minimal agent-control wire feature

[pathscale]

Summary

• add a minimal wire-core layer around the existing WireMessage, TransportStream, and framing modules
• add agent-control as the local framed control feature without server, HTTP, TLS, database, scheduler, or telemetry modules
• add small JSON-RPC 2.0 / MCP request, notification, response, and error envelopes to the built-in wire module
• move existing model and telemetry dependencies behind the existing types feature
• prepare endpoint-libs 2.1.5 for the new public feature and wire API

Verification

• cargo test -p endpoint-libs --lib --no-default-features --features agent-control (8 passed)
• cargo check -p endpoint-libs --no-default-features --features agent-control
• cargo fmt --all -- --check
• dependency surface: async-trait, bytes, eyre, futures, serde, serde_json, tokio, tokio-util

The all-feature check passed before rebasing onto 2.1.4; after rebase the sandbox refused access to one newly locked registry archive, while the focused feature checks remained green.