feat(muse-adapter): add Muse Code harness to agent-manager, CLI, and Rust devkitd

[codeaholicguy]

Summary

Adds Muse Code (muse) as a first-class harness across the stack:

• agent-manager (TS): harnesses/muse/ (session parser, locator, agent mapper, adapter, readiness) plus processNamePrefixes discovery for versioned muse-bin-* binaries; muse registered in AGENT_TYPES, runtime and readiness profiles.
• CLI: muse display labels, start-pane, status, and sessions list support.
• Rust devkitd: devkit-harness muse locator/parser, shared prefix matching, and devkit-core discovery pool gate with registry/parity wiring.
• Fixtures/docs: muse harness + readiness fixtures and lifecycle docs under docs/ai/*/.

Validation

• agent-manager: 1371 passed / 0 failed, tsc clean, oxlint 0/0
• CLI: 1332 passed, build green
• Rust: harness + core suites green, clippy 0 warnings
• Fixture replays byte-identical; live transcript parity check OK

Notes

• V1 scope is the vertical slice (detect, history, conversation, readiness); send transport and durable muse exec/resume are deferred to V2.
• Rebased onto main (includes feat(cli): add Muse Code skill install support for project and global #368) before opening.