Use linkify-it for commit description URLs

Replace the hand-rolled URL regex with `linkify-it` (already a
transitive dep via `marked-linkify-it`). Add unit tests.

tests/unit/commit.test.ts

@@ -0,0 +1,81 @@
+import { describe, expect, test } from "vitest";
+
+import * as commit from "@app/lib/commit";
+
+describe("renderCommitDescription", () => {
+  test("escapes HTML in commit text", () => {
+    expect(commit.renderCommitDescription("<script>alert(1)</script>")).toEqual(
+      "&lt;script&gt;alert(1)&lt;/script&gt;",
+    );
+  });
+
+  test("trims leading and trailing whitespace", () => {
+    expect(commit.renderCommitDescription("  hello  ")).toEqual("hello");
+  });
+
+  test("converts a bare URL into a radicle-external-link", () => {
+    expect(commit.renderCommitDescription("see https://example.com")).toEqual(
+      'see <radicle-external-link href="https://example.com">https://example.com</radicle-external-link>',
+    );
+  });
+
+  test("strips surrounding angle brackets (CommonMark autolink)", () => {
+    const out = commit.renderCommitDescription(
+      "see <https://github.com/radicle-dev/heartwood> for code",
+    );
+    expect(out).toContain('href="https://github.com/radicle-dev/heartwood"');
+    expect(out).not.toMatch(/href="[^"]*&gt;/);
+    // Autolink syntax should not produce visible angle brackets.
+    expect(out).not.toContain("&lt;");
+    expect(out).not.toContain("&gt;");
+  });
+
+  test("does not include trailing period in the link href", () => {
+    const out = commit.renderCommitDescription("see https://example.com.");
+    expect(out).toContain('href="https://example.com"');
+    expect(out).not.toContain('href="https://example.com."');
+    expect(out.endsWith(".")).toBe(true);
+  });
+
+  test("autolink followed by period: brackets stripped, period preserved", () => {
+    const out = commit.renderCommitDescription(
+      "See <https://doc.rust-lang.org/edition-guide/rust-2024/>.",
+    );
+    expect(out).toContain(
+      'href="https://doc.rust-lang.org/edition-guide/rust-2024/"',
+    );
+    expect(out).not.toContain("&lt;");
+    expect(out).not.toContain("&gt;");
+    expect(out.endsWith(".")).toBe(true);
+  });
+
+  test("does not include enclosing parentheses in the link href", () => {
+    const out = commit.renderCommitDescription("see (https://example.com)");
+    expect(out).toContain('href="https://example.com"');
+    expect(out).not.toContain('href="https://example.com)"');
+  });
+
+  test("preserves ampersands inside query strings", () => {
+    const out = commit.renderCommitDescription("https://example.com/?a=1&b=2");
+    expect(out).toContain('href="https://example.com/?a=1&amp;b=2"');
+  });
+
+  test("links multiple URLs in one description", () => {
+    const out = commit.renderCommitDescription(
+      "see https://a.example and https://b.example",
+    );
+    expect(out).toContain('href="https://a.example"');
+    expect(out).toContain('href="https://b.example"');
+  });
+
+  test("leaves text without URLs untouched", () => {
+    expect(commit.renderCommitDescription("just some plain text")).toEqual(
+      "just some plain text",
+    );
+  });
+
+  test("does not linkify text without a scheme (fuzzyLink off)", () => {
+    const out = commit.renderCommitDescription("contact foo@example.com");
+    expect(out).not.toContain("<radicle-external-link");
+  });
+});