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)) {

src/services/integrations/OpenCodeInstaller.ts

@@ -218,12 +218,16 @@ export function uninstallOpenCodePlugin(): number {
           '\n' +
           content.slice(tagEndIndex + CONTEXT_TAG_CLOSE.length).trimStart();
 
-        // If the file is now essentially empty, don't bother keeping it
-        if (content.trim().length === 0) {
+        // If the file is now essentially empty or only has our header, remove it
+        const trimmedContent = content.trim();
+        if (
+          trimmedContent.length === 0 ||
+          trimmedContent === '# Claude-Mem Memory Context'
+        ) {
           unlinkSync(agentsMdPath);
           console.log(`  Removed empty AGENTS.md`);
         } else {
-          writeFileSync(agentsMdPath, content.trimEnd() + '\n', 'utf-8');
+          writeFileSync(agentsMdPath, trimmedContent + '\n', 'utf-8');
           console.log(`  Cleaned context from AGENTS.md`);
         }
       }

src/services/integrations/WindsurfHooksInstaller.ts

@@ -278,6 +278,11 @@ export async function installWindsurfHooks(): Promise<number> {
 
   // Find bun executable — required because worker-service.cjs uses bun:sqlite
   const bunPath = findBunPath();
+  if (!bunPath) {
+    console.error('Could not find Bun runtime');
+    console.error('   Install Bun: curl -fsSL https://bun.sh/install | bash');
+    return 1;
+  }
 
   // IMPORTANT: Tilde expansion is NOT supported in working_directory — use absolute paths
   const workingDirectory = path.dirname(workerServicePath);