chore: fix installation directory handling to use .bmad-core as default path

- Remove redundant ./ prefix from default directory
- Update all default paths from ./.bmad-core to .bmad-core
- Add logic to handle direct .bmad-core path selection
- Treat parent as project root when .bmad-core specified
- Simplify directory state detection for existing files
- Remove unknown_existing state type from installer logic

tools/installer/bin/bmad.js

@@ -37,7 +37,7 @@ program
   .description('Install BMAD Method agents and tools')
   .option('-f, --full', 'Install complete .bmad-core folder')
   .option('-a, --agent <agent>', 'Install specific agent with dependencies')
-  .option('-d, --directory <path>', 'Installation directory (default: ./bmad-core)')
+  .option('-d, --directory <path>', 'Installation directory (default: .bmad-core)')
   .option('-i, --ide <ide>', 'Configure for specific IDE (cursor, claude-code, windsurf, roo)')
   .action(async (options) => {
     try {
@@ -50,7 +50,7 @@ program
         const config = {
           installType: options.full ? 'full' : 'single-agent',
           agent: options.agent,
-          directory: options.directory || './.bmad-core',
+          directory: options.directory || '.bmad-core',
           ide: options.ide
         };
         await installer.install(config);
@@ -110,7 +110,7 @@ async function promptInstallation() {
       type: 'input',
       name: 'directory',
       message: 'Where would you like to install BMAD?',
-      default: './.bmad-core'
+      default: '.bmad-core'
     }
   ]);
   answers.directory = directory;

tools/installer/lib/installer.js

@@ -12,7 +12,11 @@ class Installer {
 
     try {
       // Resolve installation directory
-      const installDir = path.resolve(config.directory);
+      let installDir = path.resolve(config.directory);
+      if (path.basename(installDir) === '.bmad-core') {
+        // If user points directly to .bmad-core, treat its parent as the project root
+        installDir = path.dirname(installDir);
+      }
 
       // Detect current state
       const state = await this.detectInstallationState(installDir);
@@ -103,9 +107,9 @@ class Installer {
     });
 
     if (files.length > 0) {
-      state.type = "unknown_existing";
+      // Directory has other files, but no BMAD installation.
+      // Treat as clean install but record that it isn't empty.
       state.hasOtherFiles = true;
-      return state;
     }
 
     return state; // clean install