Deckard host overlay

UI, ownership, clamps, and generator spellings on top of @spacedevin/deck.

Canonical language reference lives in @spacedevin/deck:

Checkout / npm: node_modules/@spacedevin/deck/docs/DECK_GRAMMAR.md
Package export: @spacedevin/deck/grammar
Upstream: github.com/spacedevin/deck

Host integration (registries, dialects): package docs/HOST.md · Deckard boot: src/generators/DeckIds.tish, src/generators/BuiltinMacros.tish.

This document is the Deckard overlay — UI, co-DJ, ownership, clamps, and generator spellings — not a second grammar.

UI: local song vs hub stream

There is a single deck editor (Apply / Sync, step highlight). Stream vs local is tied to Co-DJ:

State	deck panel
Not connected	Banner: Local — not on hub. Edit the song locally.
Co-DJ connected	Banner: Hub + Local → hub preview (what you send on Play) and Remote (agent `deck.stream_chunk` tail).

Append a line from JS (e.g. LLM tooling): call streamAppendLine on the DeckardRuntime held in App’s useRef (src/ui/DeckardRuntime.tish). Example: runtime.streamAppendLine("track kick id c0 gen noise_burst").

Host modules (not in the package)

Concern	Location
Parse / format / highlight classify	`@spacedevin/deck`
AST → project	`src/deckfile/Apply.tish`
project → deck	`src/deckfile/Emit.tish`
Incremental `deck.line`	`src/deckfile/Stream.tish`
`patch` / `matrix_fm` graphs	`PatchGraph.tish`, `MatrixFmGraph.tish`
Id / dialect registration	`DeckIds.tish`
Builtin macros	`BuiltinMacros.tish`
Ownership / skills	`src/codj/`
HTML highlight	`src/ui/SongEditorHighlight.tish`

Apply clamps (Deckard)

These are enforced when applying into a project, not by the language parser:

Line	Deckard behaviour
`bpm <n>`	Clamped 40–300
`swing`	`0..1`
Scale	Snaps melodic triggers live; peers + offline renders agree (`Scale.tish`)
`@ perf_step <n>`	Stream / Co-DJ scheduling; JSON `effectivePerfStep` on `deck.block` overrides. Song parser treats as no-op

Generator id spellings (Deckard)

Registered in ensureDeckGeneratorIds():

deck / emit	host `generatorId`
`noise_burst`	`noiseBurst`
`fm` / `fm_tone`	`fmTone`
`basic_osc` / `osc`	`basicOsc`
`matrix_fm`	`matrixFm`
`drum` / `drum_synth`	`drumSynth`
`patch` / `modular` / `synth`	`patch`

Undeclared ids pass through. Other catalog ids use the host registry spelling. Macro names expand via registerBuiltinMacros (MacroVoice.tish).

Ownership & edit fragments

remove_track <channelId> — incremental only (never in a full snapshot). Ownership-gated by actorMayEditTrack (lane removes own track; master removes any). UI × emits it; undo re-creates from captured deck.
Master-scope lines (bpm, version header, scale, swing, master_mix, actor_mix, auto, session_*, clip, …) require master_mixer — see DJ_SKILLS.md.
Co-DJ lane subset: DECK_AGENT_GRAMMAR.md.

Control directives in Co-DJ

Language @ … table: package grammar. Deckard wire + authority: STREAM_PROTOCOL.md, WS_AND_AGENTS.md.

DECK_EXTENSION.md — Deckard patch / matrix_fm engines
Package extension dialect syntax: @spacedevin/deck/extension