Fix path resolution and symlink removal in Codex installer

Use fileURLToPath() instead of manual URL pathname parsing to correctly
handle paths with spaces and special characters on all platforms.
Replace execSync rm/rmdir with fs.unlinkSync for stale symlink removal.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.codex/install-codex.mjs

@@ -4,8 +4,9 @@
 // Creates a symlink from ~/.agents/skills/superpowers → repo skills/
 // and updates ~/.codex/AGENTS.md with a gatekeeper block.
 
-import { existsSync, readFileSync, writeFileSync, mkdirSync, symlinkSync, lstatSync, readlinkSync } from 'fs';
-import { join, resolve } from 'path';
+import { existsSync, readFileSync, writeFileSync, mkdirSync, symlinkSync, lstatSync, readlinkSync, unlinkSync } from 'fs';
+import { join, resolve, dirname } from 'path';
+import { fileURLToPath } from 'url';
 import { homedir, platform } from 'os';
 import { execSync } from 'child_process';
 
@@ -13,7 +14,8 @@ const home = homedir();
 const isWindows = platform() === 'win32';
 
 // Paths
-const repoSkillsDir = resolve(new URL('.', import.meta.url).pathname.replace(/^\/([A-Z]:)/i, '$1'), '..', 'skills');
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const repoSkillsDir = resolve(__dirname, '..', 'skills');
 const agentsSkillsDir = join(home, '.agents', 'skills');
 const symlinkPath = join(agentsSkillsDir, 'superpowers');
 const agentsMdPath = join(home, '.codex', 'AGENTS.md');
@@ -52,7 +54,7 @@ function createSymlink() {
           return;
         }
         console.log(`! Existing symlink points to ${target}, updating to ${repoSkillsDir}`);
-        execSync(isWindows ? `rmdir "${symlinkPath}"` : `rm "${symlinkPath}"`);
+        unlinkSync(symlinkPath);
       } else {
         console.error(`✗ ${symlinkPath} already exists and is not a symlink.`);
         console.error(`  Remove it manually and re-run the installer.`);