Add bundled TTF fonts, page geometry, column allocator and render model

Static TTF fonts (IBM Plex Sans/Mono, Noto Devanagari/Kannada) with a
fontkit-generated manifest, a verifier and OFL licences. Every family
registers a normal and italic source so fallback stacks cannot throw.
Adds A4/Letter geometry with margin presets, an exact column allocator,
deterministic Indian-grouping money and date formatting, text sanitising
and a pure buildRenderModel.

src/pdf/fonts/manifest.ts

@@ -0,0 +1,35 @@
+import manifestJson from "../../../public/fonts/manifest.json";
+
+export interface FontFileEntry {
+  file: string;
+  weight: number;
+  style: "normal" | "italic";
+  sha256: string;
+  fsType: number;
+  upm: number;
+  ascent: number;
+  descent: number;
+  lineGap: number;
+  capHeight: number;
+  xHeight: number;
+  hasRupee: boolean;
+  hasTabularNums: boolean;
+}
+
+export interface FontFamilyEntry {
+  family: string;
+  folder: string;
+  license: string;
+  licenseFile: string;
+  fonts: FontFileEntry[];
+}
+
+export interface FontManifest {
+  version: 1;
+  families: FontFamilyEntry[];
+}
+
+// Generated by scripts/fonts/build-manifest.mjs.
+export const FONT_MANIFEST = manifestJson as FontManifest;
+
+export const FONT_FAMILIES: readonly string[] = FONT_MANIFEST.families.map((f) => f.family);