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/screen/_section.md

@@ -0,0 +1,7 @@
+---
+id: screen
+title: Screen — drawing
+order: 5
+---
+
+The 2D drawing surface. Every call takes named arguments; draw during the <code>Render</code> phase, then <code>Screen.show()</code>.

docs/language/screen/screen-clear.md

@@ -0,0 +1,16 @@
+---
+id: screen-clear
+name: Screen.clear
+category: screen
+kind: namespace-method
+tokens: Screen.clear
+sig: Screen.clear(color)
+tip: Fill the entire screen with one color.
+order: 0
+---
+
+Fill the entire screen with one color.
+
+```ludic
+Screen.clear(Color.MidnightBlue)
+```

docs/language/screen/screen-draw_number.md

@@ -0,0 +1,16 @@
+---
+id: screen-draw_number
+name: Screen.draw_number
+category: screen
+kind: namespace-method
+tokens: Screen.draw_number
+sig: Screen.draw_number(x, y, value, color, scale)
+tip: Draw an integer — no allocation, no string conversion.
+order: 5
+---
+
+Draw an integer — no allocation, no string conversion.
+
+```ludic
+Screen.draw_number(x: 52, y: 4, value: score, color: Color.Gold, scale: 1)
+```

docs/language/screen/screen-draw_rectangle.md

@@ -0,0 +1,12 @@
+---
+id: screen-draw_rectangle
+name: Screen.draw_rectangle
+category: screen
+kind: namespace-method
+tokens: Screen.draw_rectangle
+sig: Screen.draw_rectangle(x, y, width, height, color)
+tip: Draw a one-pixel rectangle outline.
+order: 2
+---
+
+Draw a one-pixel rectangle outline.

docs/language/screen/screen-draw_text.md

@@ -0,0 +1,16 @@
+---
+id: screen-draw_text
+name: Screen.draw_text
+category: screen
+kind: namespace-method
+tokens: Screen.draw_text
+sig: Screen.draw_text(x, y, text, color, scale)
+tip: Draw a string with the built-in font at an integer scale.
+order: 4
+---
+
+Draw a string with the built-in font at an integer scale.
+
+```ludic
+Screen.draw_text(x: 6, y: 4, text: "SCORE", color: Color.White, scale: 1)
+```

docs/language/screen/screen-fill_rectangle.md

@@ -0,0 +1,16 @@
+---
+id: screen-fill_rectangle
+name: Screen.fill_rectangle
+category: screen
+kind: namespace-method
+tokens: Screen.fill_rectangle
+sig: Screen.fill_rectangle(x, y, width, height, color)
+tip: Draw a filled rectangle.
+order: 1
+---
+
+Draw a filled rectangle.
+
+```ludic
+Screen.fill_rectangle(x: 8, y: 8, width: 16, height: 16, color: Color.Crimson)
+```

docs/language/screen/screen-height.md

@@ -0,0 +1,12 @@
+---
+id: screen-height
+name: Screen.height
+category: screen
+kind: namespace-method
+tokens: Screen.height
+sig: Screen.height() -> int
+tip: Framebuffer height in pixels.
+order: 8
+---
+
+Framebuffer height in pixels.

docs/language/screen/screen-put_pixel.md

@@ -0,0 +1,12 @@
+---
+id: screen-put_pixel
+name: Screen.put_pixel
+category: screen
+kind: namespace-method
+tokens: Screen.put_pixel
+sig: Screen.put_pixel(x, y, color)
+tip: Set a single pixel.
+order: 3
+---
+
+Set a single pixel.

docs/language/screen/screen-show.md

@@ -0,0 +1,16 @@
+---
+id: screen-show
+name: Screen.show
+category: screen
+kind: namespace-method
+tokens: Screen.show
+sig: Screen.show()
+tip: Present the finished frame — copy everything you have drawn to the window.
+order: 6
+---
+
+Present the finished frame — copy everything you have drawn to the window. Call it once, last, in your Render handler.
+
+```ludic
+Screen.show()
+```

docs/language/screen/screen-status.md

@@ -0,0 +1,12 @@
+---
+id: screen-status
+name: Screen.status
+category: screen
+kind: namespace-method
+tokens: Screen.status
+sig: Screen.status(text)
+tip: Set the persistent one-line status/HUD string.
+order: 9
+---
+
+Set the persistent one-line status/HUD string.

docs/language/screen/screen-width.md

@@ -0,0 +1,12 @@
+---
+id: screen-width
+name: Screen.width
+category: screen
+kind: namespace-method
+tokens: Screen.width
+sig: Screen.width() -> int
+tip: Framebuffer width in pixels.
+order: 7
+---
+
+Framebuffer width in pixels.