docs: automated documentation pipeline (per-symbol source → pages)

Replace the hardcoded landing page and minimal reference with a generated
documentation site driven by a single source of truth.

- docs/language/**: one file per symbol (93 keywords/types/builtins/namespace
  methods/operators/annotations), each with front-matter (id, kind, tokens,
  sig, tip) + description + a ```ludic example. Seeded by exploding the former
  inline SECTIONS list; these files are now the source of truth.
- docs/site/: site.json (editable hero/features/showcase/messaging, not
  hardcoded) + snippets/*.ludic (real programs shown on the landing page).
- tools/docgen/gen.py: generates index.html, api.html, ludic-highlight.js and
  symbols.json. The highlighter's symbol tables, hover tips and jump anchors
  are GENERATED from the per-symbol files — add a symbol and it is recognized,
  tipped and linked in every snippet automatically. Python stdlib only.
- tools/docgen/check.py: verifies the pages contract + that no snippet token
  links to a missing reference anchor.
- .forgejo/workflows/docs.yml: rebuilds and publishes to the pages branch on
  every push to main touching the docs sources.

Consumes the new Screen.*/Color.*/named-arg API and the 221-color palette.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/language/ecs/_section.md

@@ -0,0 +1,7 @@
+---
+id: ecs
+title: Entities & the ECS
+order: 1
+---
+
+Entities are ids; properties are their data; queries walk them.

docs/language/ecs/fn-world_get.md

@@ -0,0 +1,12 @@
+---
+id: fn-world_get
+name: world_get / world_set / world_has …
+category: ecs
+kind: builtin
+tokens: world_get world_set world_has world_count world_spawn
+sig: world_get(entity, prop, field) -> int
+tip: The reflection ABI: read and write the world by numeric id, for tools and mods.
+order: 8
+---
+
+The reflection ABI: read and write the world by numeric id, for tools and mods. See also world_count, world_spawn.

docs/language/ecs/kw-attach.md

@@ -0,0 +1,12 @@
+---
+id: kw-attach
+name: attach
+category: ecs
+kind: keyword
+tokens: attach
+sig: attach Prop on entity { overrides }
+tip: Add a property to a live entity.
+order: 6
+---
+
+Add a property to a live entity.

docs/language/ecs/kw-despawn.md

@@ -0,0 +1,12 @@
+---
+id: kw-despawn
+name: despawn
+category: ecs
+kind: keyword
+tokens: despawn
+sig: despawn entity
+tip: Remove an entity.
+order: 1
+---
+
+Remove an entity. Inside a query, <code>despawn self()</code> removes the current match.

docs/language/ecs/kw-detach.md

@@ -0,0 +1,12 @@
+---
+id: kw-detach
+name: detach
+category: ecs
+kind: keyword
+tokens: detach
+sig: detach Prop on entity
+tip: Remove a property from a live entity.
+order: 7
+---
+
+Remove a property from a live entity.

docs/language/ecs/kw-disable.md

@@ -0,0 +1,12 @@
+---
+id: kw-disable
+name: disable
+category: ecs
+kind: keyword
+tokens: disable
+sig: disable Prop on entity
+tip: Deactivate a property without destroying its data.
+order: 5
+---
+
+Deactivate a property without destroying its data. Also <code>disable Model</code> / a whole handler.

docs/language/ecs/kw-enable.md

@@ -0,0 +1,12 @@
+---
+id: kw-enable
+name: enable
+category: ecs
+kind: keyword
+tokens: enable
+sig: enable Prop on entity
+tip: Re-activate a disabled property; its stored values are intact.
+order: 4
+---
+
+Re-activate a disabled property; its stored values are intact.

docs/language/ecs/kw-query.md

@@ -0,0 +1,16 @@
+---
+id: kw-query
+name: query
+category: ecs
+kind: keyword
+tokens: query
+sig: query [PropA, PropB, {Tag}]
+tip: Match every entity that carries all listed properties.
+order: 2
+---
+
+Match every entity that carries all listed properties. Use it in <code>for (a, b) in query […]</code>; a <code>{Tag}</code> filters without binding.
+
+```ludic
+for (p, s) in query [Pos, Seg] { … }
+```

docs/language/ecs/kw-self.md

@@ -0,0 +1,12 @@
+---
+id: kw-self
+name: self
+category: ecs
+kind: keyword
+tokens: self
+sig: self()
+tip: The entity currently bound by the enclosing query.
+order: 3
+---
+
+The entity currently bound by the enclosing query.

docs/language/ecs/kw-spawn.md

@@ -0,0 +1,16 @@
+---
+id: kw-spawn
+name: spawn
+category: ecs
+kind: keyword
+tokens: spawn
+sig: spawn Label { Prop { field: v }; … }
+tip: Create an entity carrying the listed properties (or a model).
+order: 0
+---
+
+Create an entity carrying the listed properties (or a model). The label is for readability.
+
+```ludic
+spawn Body { Seg { order: 1 }; Pos { x: 9, y: 7 } }
+```