fix: address second PR review — clean replace, IDE failure bubbling, bun validation

- cpSync now does rmSync before copy to avoid stale file merges
- setupIDEs() returns failed IDE list; install reports partial success
- runSmartInstall() returns boolean status instead of void
- Worker port in next-steps URL reads CLAUDE_MEM_WORKER_PORT env var
- Goose YAML regex stops at column-0 keys (prevents eating sibling sections)
- AGENTS.md uninstall removes header-only stub files
- findBunPath() validated before use in WindsurfHooksInstaller
- Cursor marked unsupported in ide-detection until installer is wired

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/services/integrations/McpIntegrations.ts

@@ -285,7 +285,7 @@ export async function installGooseMcpIntegration(): Promise<number> {
       if (gooseConfigHasClaudeMemEntry(yamlContent)) {
         // Already configured — replace the claude-mem block
         // Find the claude-mem entry and replace it
-        const claudeMemPattern = /( {2}claude-mem:\n(?:.*\n)*?(?= {2}\S|\n\n|$))/;
+        const claudeMemPattern = /( {2}claude-mem:\n(?:.*\n)*?(?= {2}\S|\n\n|^\S|$))/m;
         const newEntry = buildGooseClaudeMemEntryYaml(mcpServerPath) + '\n';
 
         if (claudeMemPattern.test(yamlContent)) {