Claude/windows install compatibility tr di s (#3)

* Fix Windows PowerShell 5.1 compatibility in installer

Use $env:PROCESSOR_ARCHITECTURE for arch detection instead of
RuntimeInformation::OSArchitecture which may not be loaded in
every Windows PowerShell 5.1 session. Also fix null-reference
when user PATH environment variable is empty.

https://claude.ai/code/session_01VFiRDM2ZweyacXN5JneVoP

* Fix executable resolution and tar extraction on Windows

resolveExecutable() used `sh -lc "command -v ..."` which doesn't work
on Windows (no sh). Now uses `cmd /c where` on win32. Also make tar
workspace restoration tolerate symlink failures on Windows — .bin/
symlinks can't be created without Developer Mode, but the actual
package directories are extracted fine.

https://claude.ai/code/session_01VFiRDM2ZweyacXN5JneVoP

* Broad Windows compatibility fixes across the codebase

- runtime.ts: Use path.delimiter instead of hardcoded ":" for PATH
  construction — was completely broken on Windows
- executables.ts: Add Windows fallback paths for Chrome, Edge, Brave,
  and Pandoc in Program Files; skip macOS-only paths on win32
- node-version.ts, check-node-version.mjs, bin/feynman.js: Show
  Windows-appropriate install instructions (irm | iex, nodejs.org)
  instead of nvm/curl on win32
- preview.ts: Support winget for pandoc auto-install on Windows, and
  apt on Linux (was macOS/brew only)
- launch.ts: Catch unsupported signal errors on Windows
- README.md: Add Windows PowerShell commands alongside macOS/Linux
  for all install instructions

https://claude.ai/code/session_01VFiRDM2ZweyacXN5JneVoP

* fix: complete windows bootstrap hardening

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Advait Paliwal <advaitspaliwal@gmail.com>

scripts/patch-embedded-pi.mjs

@@ -139,12 +139,18 @@ function restorePackagedWorkspace(packageSpecs) {
 		timeout: 300000,
 	});
 
+	// On Windows, tar may exit non-zero due to symlink creation failures in
+	// .bin/ directories. These are non-fatal — check whether the actual
+	// package directories were extracted successfully.
+	const packagesPresent = packageSpecs.every((spec) => existsSync(resolve(workspaceRoot, parsePackageName(spec))));
+	if (packagesPresent) return true;
+
 	if (result.status !== 0) {
 		if (result.stderr?.length) process.stderr.write(result.stderr);
 		return false;
 	}
 
-	return packageSpecs.every((spec) => existsSync(resolve(workspaceRoot, parsePackageName(spec))));
+	return false;
 }
 
 function refreshPackagedWorkspace(packageSpecs) {
@@ -156,12 +162,18 @@ function resolveExecutable(name, fallbackPaths = []) {
 		if (existsSync(candidate)) return candidate;
 	}
 
-	const result = spawnSync("sh", ["-lc", `command -v ${name}`], {
-		encoding: "utf8",
-		stdio: ["ignore", "pipe", "ignore"],
-	});
+	const isWindows = process.platform === "win32";
+	const result = isWindows
+		? spawnSync("cmd", ["/c", `where ${name}`], {
+				encoding: "utf8",
+				stdio: ["ignore", "pipe", "ignore"],
+			})
+		: spawnSync("sh", ["-lc", `command -v ${name}`], {
+				encoding: "utf8",
+				stdio: ["ignore", "pipe", "ignore"],
+			});
 	if (result.status === 0) {
-		const resolved = result.stdout.trim();
+		const resolved = result.stdout.trim().split(/\r?\n/)[0];
 		if (resolved) return resolved;
 	}
 	return null;
@@ -541,6 +553,11 @@ if (alphaHubAuthPath && existsSync(alphaHubAuthPath)) {
 	if (source.includes(oldError)) {
 		source = source.replace(oldError, newError);
 	}
+	const brokenWinOpen = "else if (plat === 'win32') execSync(`start \"${url}\"`);";
+	const fixedWinOpen = "else if (plat === 'win32') execSync(`cmd /c start \"\" \"${url}\"`);";
+	if (source.includes(brokenWinOpen)) {
+		source = source.replace(brokenWinOpen, fixedWinOpen);
+	}
 	writeFileSync(alphaHubAuthPath, source, "utf8");
 }