docs/language: a page for every keyword and attribute the vocabulary has

Keywords: module uses friend export internal numbers unsafe mut port bind action
reducer registry of as from def open alias component prop view (structure),
shows lasts then loads (scenes), system (ecs), dispatch (control), true false
null (operators). Attributes: @Ref @OneOf @Range @Unit @Asset @Color, @Node /
@Clip / @Material, @Tint @Derived, @Text / @Multiline, @Key, @AppendOnly /
@ByKey, @PerMap / @Chunked, @frame @max, @owns / @creates / @releases,
@deterministic @alloc_ok. Each is in tools/docgen/inventory.json; every fence
that is not marked skip parses (ludicc --fmt). annot-clearcolor's token loses its
quotes, which no reader strips.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/language/annotations/annot-unit.md

@@ -0,0 +1,12 @@
+---
+id: annot-unit
+name: @Unit
+category: annotations
+kind: annotation
+tokens: @Unit
+sig: @Unit("m/s") field: float = 0.0
+tip: The value's unit, in one canonical ASCII spelling.
+order: 66
+---
+
+<code>@Unit</code> takes one of <code>m</code>, <code>m/s</code>, <code>m/s2</code>, <code>s</code>, <code>min</code>, <code>h</code>, <code>d</code>, <code>deg</code>, <code>rad</code>, <code>rad/s</code>, <code>kg</code>, <code>N</code>, <code>N.m</code>, <code>%</code>, <code>px</code>, so one word means one unit to an editor; another spelling is a warning naming the canonical one.