Add typography roles, text primitives, fontkit measurer and layout lint

Txt always sets an absolute line height; RenderTxt never does. Row pins
every cell and stacks when the fill column would be too narrow. IdText and
FitText shrink then chunk or truncate. The fontkit measurer matches react-pdf
text widths exactly. A TypeScript-AST lint test enforces the layout rules
(no lineHeight outside Txt, no non-literal fixed/wrap/minPresenceAhead,
flexGrow needs flexBasis, no stray absolute positioning).

package.json

@@ -27,6 +27,7 @@
     "@tauri-apps/api": "^2.12.1",
     "@tauri-apps/plugin-dialog": "^2.8.1",
     "@tauri-apps/plugin-opener": "^2.7.0",
+    "fontkit": "2.0.4",
     "react": "^19.3.0",
     "react-dom": "^19.3.0",
     "react-is": "^19.3.0"
@@ -37,7 +38,6 @@
     "@types/react": "^19.2.0",
     "@types/react-dom": "^19.2.0",
     "@vitejs/plugin-react": "^5.2.0",
-    "fontkit": "2.0.4",
     "pdfjs-dist": "6.4.299",
     "sass": "^1.105.1",
     "typescript": "^5.9.3",