Added minimal LSP server entrypoint supporting initialize/shutdown/exit
handshake over JSON-RPC stdin/stdout transport with Content-Length
framing. Unsupported methods return MethodNotFound error with descriptive
message. Wired LSP requests through ACP facade in local mode. Added
agents lsp serve CLI command with --log-level flag, PID output, and
startup banner. Created reference documentation for the stub server.
Includes Behave BDD tests for protocol handshake, Robot smoke test, and
ASV startup latency benchmark.
ISSUES CLOSED: #203
CoreRasurae
