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/render.test.tsx

@@ -0,0 +1,31 @@
+import { createElement as h } from "react";
+import path from "node:path";
+import { renderToBuffer, Document, Page, Text } from "@react-pdf/renderer";
+import { describe, expect, it } from "vitest";
+import { registerBundledFonts, stack } from "./register";
+
+registerBundledFonts(path.resolve(process.cwd(), "public/fonts"));
+
+const render = (page: object, style: object) =>
+  renderToBuffer(
+    h(Document, null, h(Page, page as never, h(Text, { style: style as never }, "Total ₹1,23,456.78 नमस्ते ಕನ್ನಡ"))),
+  );
+
+describe("bundled fonts render", () => {
+  it("renders every family-stack in italic and bold-italic without throwing", async () => {
+    for (const fontWeight of [300, 400, 500, 600, 700]) {
+      const buf = await render({ size: "A4" }, { fontFamily: stack("IBM Plex Sans"), fontStyle: "italic", fontWeight });
+      expect(buf.subarray(0, 5).toString()).toBe("%PDF-");
+    }
+    const mono = await render({ size: "A4" }, { fontFamily: stack("IBM Plex Mono"), fontStyle: "italic", fontWeight: 600 });
+    expect(mono.length).toBeGreaterThan(1000);
+  });
+
+  it("accepts mm strings in the Page size object", async () => {
+    const buf = await render({ size: { width: "210mm", height: "297mm" } }, { fontFamily: stack("IBM Plex Sans") });
+    const m = /\/MediaBox \[0 0 ([\d.]+) ([\d.]+)\]/.exec(buf.toString("latin1"));
+    expect(m).not.toBeNull();
+    expect(Number(m![1])).toBeCloseTo(595.28, 1);
+    expect(Number(m![2])).toBeCloseTo(841.89, 1);
+  });
+});