fix(installer): guard ExistingInstall.version and surface module.yaml errors

Guard ExistingInstall.version access with .installed check in
uninstall.js, ui.js, and installer.js to prevent throwing on
empty/partial _bmad dirs. Surface invalid module.yaml parse errors
as warnings instead of silently returning empty results.

tools/installer/commands/uninstall.js

@@ -62,7 +62,7 @@ module.exports = {
       }
 
       const existingInstall = await installer.getStatus(projectDir);
-      const version = existingInstall.version || 'unknown';
+      const version = existingInstall.installed ? existingInstall.version : 'unknown';
       const modules = existingInstall.moduleIds.join(', ');
       const ides = existingInstall.ides.join(', ');
 

tools/installer/core/installer.js

@@ -1360,7 +1360,7 @@ class Installer {
       removed.modules = await this.uninstallModules(projectDir);
     }
 
-    return { success: true, removed, version: existingInstall.version };
+    return { success: true, removed, version: existingInstall.installed ? existingInstall.version : null };
   }
 
   /**

tools/installer/modules/official-modules.js

@@ -484,8 +484,9 @@ class OfficialModules {
     try {
       const yamlContent = await fs.readFile(moduleYamlPath, 'utf8');
       moduleYaml = yaml.parse(yamlContent);
-    } catch {
-      return emptyResult; // Invalid YAML, skip
+    } catch (error) {
+      await prompts.log.warn(`Invalid module.yaml for ${moduleName}: ${error.message}`);
+      return emptyResult;
     }
 
     if (!moduleYaml || !moduleYaml.directories) {

tools/installer/ui.js

@@ -72,7 +72,7 @@ class UI {
       const { existingInstall, bmadDir } = await this.getExistingInstallation(confirmedDirectory);
       const packageJsonPath = path.join(__dirname, '../../package.json');
       const currentVersion = require(packageJsonPath).version;
-      const installedVersion = existingInstall.version || 'unknown';
+      const installedVersion = existingInstall.installed ? existingInstall.version || 'unknown' : 'unknown';
 
       // Build menu choices dynamically
       const choices = [];