ci: verify on windows-latest + fix cross-platform build bugs it surfaced (#342)

* fix(cli): make build copy cross-platform and deterministic

* fix(core): keep rewritten asset URLs POSIX on Windows

* ci(windows): add render verification workflow

* ci(windows): load canary gsap from cdn

* build: use dependency-aware workspace ordering

* Revert "build: use dependency-aware workspace ordering"

This reverts commit 99bc2ffbdf.

packages/core/src/compiler/rewriteSubCompPaths.test.ts

@@ -0,0 +1,39 @@
+import { describe, expect, it } from "vitest";
+import { rewriteAssetPath, rewriteCssAssetUrls } from "./rewriteSubCompPaths.js";
+
+describe("rewriteAssetPath", () => {
+  it("rewrites `../` against the sub-composition dir", () => {
+    expect(rewriteAssetPath("compositions/scene.html", "../icon.svg")).toBe("icon.svg");
+  });
+
+  it("leaves plain relative paths untouched", () => {
+    expect(rewriteAssetPath("compositions/scene.html", "assets/logo.png")).toBe("assets/logo.png");
+  });
+
+  it("leaves absolute URLs and data URIs untouched", () => {
+    expect(rewriteAssetPath("compositions/scene.html", "https://x/y")).toBe("https://x/y");
+    expect(rewriteAssetPath("compositions/scene.html", "data:image/png;base64,AA")).toBe(
+      "data:image/png;base64,AA",
+    );
+    expect(rewriteAssetPath("compositions/scene.html", "#hash")).toBe("#hash");
+  });
+
+  // Regression guard for a Windows-only bug: the rewriter used to import
+  // `path` (native) and emit `:\fonts\brand.woff2` — native `join` used
+  // backslashes, and `resolve("/", x).slice(1)` chopped the `D` off a
+  // `D:\…` absolute path. URLs must be POSIX regardless of host OS.
+  it("never emits backslashes on any platform", () => {
+    const out = rewriteAssetPath("compositions/nested/scene.html", "../../fonts/brand.woff2");
+    expect(out).toBe("fonts/brand.woff2");
+    expect(out).not.toMatch(/\\/);
+    expect(out).not.toMatch(/^:/);
+  });
+
+  it("CSS url(...) rewrites also stay POSIX under nesting", () => {
+    const css = `@font-face { src: url("../../fonts/brand.woff2") format("woff2"); }`;
+    const out = rewriteCssAssetUrls(css, "compositions/nested/scene.html");
+    expect(out).toContain(`url("fonts/brand.woff2")`);
+    expect(out).not.toMatch(/\\/);
+    expect(out).not.toMatch(/:\\/);
+  });
+});

packages/core/src/compiler/rewriteSubCompPaths.ts

@@ -12,7 +12,11 @@
  * to ensure consistent behavior.
  */
 
-import { join, resolve, dirname } from "path";
+// URL paths in HTML output are POSIX regardless of host OS — use the `posix`
+// submodule so Windows builds don't emit backslash-separated paths (or worse,
+// drive-letter-prefixed artifacts from `resolve("/", ...)`).
+import { posix } from "path";
+const { join, resolve, dirname } = posix;
 
 /** Attributes that may contain relative asset paths. */
 const PATH_ATTRS = ["src", "href"] as const;