crates/mcp (lightcraft-mcp, L5): hand-written MCP over stdio (JSON-RPC 2.0,
protocol 2025-06-18 with 2025-03-26/2024-11-05 negotiation): initialize,
ping, tools/list, tools/call, resources/list/read. Two backends behind one
trait: Headless (in-process engine Session; answers engine.execute,
engine.commands, ui.render, app.export) and Remote (the desktop app's
loopback JSON-lines control channel; lazy connect + reconnect).
Tools: helpers (list_commands, run_command, import, query_photos,
select_photos, list_controls, get/set_develop, apply_preset, crop,
render_photo -> image content, export), UI tools when connected
(screenshot -> image content, inspect_ui, set_ui, list_widgets, click,
press_key, type_text, pointer_gesture), plus one cmd_<id> tool generated
per command in the registry (--compact omits them).
apps/lightcraft-cli: `mcp [--connect [ADDR]] [--demo] [--compact] [FILES]`,
`render <in> -o <out> [--set control=value]... [--settings] [--preset]
[--size] [--quality]`, `commands`, `controls`.
Acceptance e2e: crates/mcp/tests/e2e.rs sets exposure over MCP and renders
(headless and through the TCP transport); apps/lightcraft-cli/tests/cli.rs
does the same through the real binary's stdio. Docs: docs/mcp.md,
docs/control-protocol.md. Also rustfmt of one line in pipeline/finish.rs
(main was not fmt-clean).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
