fix: replace stale Free Tier with Demo tier in Terms of Service (BUG-104)

- Section 2.1: replaced Free Tier (100 PDFs, 10 req/min) with Demo (Free) - no account, 5 req/hr, evaluation only
- Section 5.1: changed 'no SLA for free tier' to 'no SLA for demo usage'
- Added terms-content regression test (3 tests)
- 487 tests passing across 33 files

src/__tests__/terms-content.test.ts

@@ -0,0 +1,24 @@
+import { describe, it, expect } from "vitest";
+import { readFileSync } from "fs";
+import { resolve } from "path";
+
+describe("Terms of Service content", () => {
+  const termsPath = resolve(__dirname, "../../public/src/terms.html");
+  const terms = readFileSync(termsPath, "utf-8");
+
+  it("should not reference discontinued Free Tier", () => {
+    expect(terms).not.toContain("Free Tier");
+    expect(terms).not.toContain("100 PDF conversions");
+  });
+
+  it("should describe the Demo tier", () => {
+    expect(terms).toContain("Demo (Free)");
+    expect(terms).toContain("5 requests per hour");
+    expect(terms).toContain("Testing and evaluation");
+  });
+
+  it("should reference demo usage not free tier in SLA section", () => {
+    expect(terms).not.toMatch(/no SLA for free tier/i);
+    expect(terms).toContain("no SLA for demo usage");
+  });
+});