lace becomes standalone: core dissolution, async jobs, ACP alignment

obra/lace

An agent runtime — the harness that runs coding-agent sessions.

The structural story is core dissolution. Tools, providers, MCP, workspace, config, utils, token-management, and the compaction strategies all moved out of @lace/core into @lace/agent; the web layer dropped its core imports; and @lace/core was deleted outright — the agent now stands alone. The protocol aligned to ACP along the way: new session/update event types, session/fork, $/cancel_request replacing the old cancel, a tightened SessionId format, token-usage and context-breakdown methods, and per-agent tool policies.

Two systems landed that shape how the runtime works day to day. An async background-jobs system: bash and delegate gained a background parameter, with job_output / jobs_list / job_kill tools, a notification queue, completion and progress notifications, job resume for delegate, and concurrency and output-size limits. And a ground-up TUI redesign: semantic color tokens, conversation-as-primary view, inline tool-call and permission display, token usage in the status bar, image paste, a slash-command picker, and MCP-config and context-usage panels. Underneath, an agent-as-library refactor introduced Agent / Session / ConversationRunner classes and decomposed the monolithic server into focused RPC handler modules. Sole contributor: Jesse Vincent.