fix: compile agents now checks multiple source locations

## Problem
Compile Agents ignored custom agents in source locations like:
- {project-root}/custom/src/agents/
- {bmad-folder}/custom/src/agents/

## Solution
Update reinstallCustomAgents to check all locations:
1. _cfg/custom/agents/ (backup location)
2. {bmad-folder}/custom/src/agents/ (source in BMAD folder)
3. {project-root}/custom/src/agents/ (source at project root)

## Changes
- Search multiple locations for agents during compile
- Avoid duplicate processing with Set tracking
- Auto-backup source YAML to _cfg/custom/agents/ if needed
- Works with any custom bmad_folder name from config

Now 'Compile Agents' works with agents in any source location!

tools/cli/installers/lib/core/installer.js

@@ -2265,21 +2265,13 @@ class Installer {
   }
 
   /**
-   * Reinstall custom agents from _cfg/custom/agents/ sources
+   * Reinstall custom agents from backup and source locations
    * This preserves custom agents across quick updates/reinstalls
    * @param {string} projectDir - Project directory
    * @param {string} bmadDir - BMAD installation directory
    * @returns {Object} Result with count and agent names
    */
   async reinstallCustomAgents(projectDir, bmadDir) {
-    const customAgentsCfgDir = path.join(bmadDir, '_cfg', 'custom', 'agents');
-    const results = { count: 0, agents: [] };
-
-    if (!(await fs.pathExists(customAgentsCfgDir))) {
-      return results;
-    }
-
-    try {
     const {
       discoverAgents,
       loadAgentConfig,
@@ -2290,20 +2282,41 @@ class Installer {
     } = require('../../../lib/agent/installer');
     const { compileAgent } = require('../../../lib/agent/compiler');
 
-      // Discover custom agents in _cfg/custom/agents/
-      const agents = discoverAgents(customAgentsCfgDir);
+    const results = { count: 0, agents: [] };
 
-      if (agents.length === 0) {
+    // Check multiple locations for custom agents
+    const sourceLocations = [
+      path.join(bmadDir, '_cfg', 'custom', 'agents'), // Backup location
+      path.join(bmadDir, 'custom', 'src', 'agents'), // BMAD folder source location
+      path.join(projectDir, 'custom', 'src', 'agents'), // Project root source location
+    ];
+
+    let foundAgents = [];
+    let processedAgents = new Set(); // Track to avoid duplicates
+
+    // Discover agents from all locations
+    for (const location of sourceLocations) {
+      if (await fs.pathExists(location)) {
+        const agents = discoverAgents(location);
+        // Only add agents we haven't processed yet
+        const newAgents = agents.filter((agent) => !processedAgents.has(agent.name));
+        foundAgents.push(...newAgents);
+        for (const agent of newAgents) processedAgents.add(agent.name);
+      }
+    }
+
+    if (foundAgents.length === 0) {
       return results;
     }
 
+    try {
       const customAgentsDir = path.join(bmadDir, 'custom', 'agents');
       await fs.ensureDir(customAgentsDir);
 
       const manifestFile = path.join(bmadDir, '_cfg', 'agent-manifest.csv');
       const manifestYamlFile = path.join(bmadDir, '_cfg', 'manifest.yaml');
 
-      for (const agent of agents) {
+      for (const agent of foundAgents) {
         try {
           const agentConfig = loadAgentConfig(agent.yamlFile);
           const finalAgentName = agent.name; // Already named correctly from save
@@ -2338,6 +2351,16 @@ class Installer {
           // Write compiled agent
           await fs.writeFile(compiledPath, xml, 'utf8');
 
+          // Backup source YAML to _cfg/custom/agents if not already there
+          const cfgAgentsBackupDir = path.join(bmadDir, '_cfg', 'custom', 'agents');
+          await fs.ensureDir(cfgAgentsBackupDir);
+          const backupYamlPath = path.join(cfgAgentsBackupDir, `${finalAgentName}.agent.yaml`);
+
+          // Only backup if source is not already in backup location
+          if (agent.yamlFile !== backupYamlPath) {
+            await fs.copy(agent.yamlFile, backupYamlPath);
+          }
+
           // Copy sidecar files if expert agent
           if (agent.hasSidecar && agent.type === 'expert') {
             const { copySidecarFiles } = require('../../../lib/agent/installer');