Add real-time GitHub sync to installers and sync script

Interactive installer (interactive-install-claude.sh):
- Add fetch_latest_agents() function to check GitHub for updates
- Clone latest agents from contains-studio/agents before installing
- Update local agents directory with upstream changes
- Gracefully fallback to local agents if GitHub fetch fails
- Call fetch_latest_agents() before install_agents() in main flow

Sync script (sync-agents.sh):
- Add REPO_AGENTS_DIR environment variable support
- Automatically update repository agents directory when syncing
- Keep installer agents in sync with Claude Code agents

This ensures users always get the latest agents from upstream GitHub
while maintaining customizations in the local repository.

sync-agents.sh

@@ -137,6 +137,25 @@ sync_agents() {
     # Summary
     local total_changes=$((${#new_agents[@]} + ${#updated_agents[@]}))
     log "INFO" "Sync complete: ${#new_agents[@]} new, ${#updated_agents[@]} updated, ${#custom_agents[@]} preserved"
+
+    # If REPO_AGENTS_DIR is set, also update repository agents
+    if [[ -n "${REPO_AGENTS_DIR:-}" && -d "$REPO_AGENTS_DIR" ]]; then
+        print_msg "$BLUE" "📦 Updating repository agents directory..."
+
+        for category in engineering marketing product studio-operations project-management testing design bonus; do
+            if [ -d "$AGENTS_DIR/$category" ]; then
+                mkdir -p "$REPO_AGENTS_DIR/$category"
+                cp -f "$AGENTS_DIR/$category"/*.md "$REPO_AGENTS_DIR/$category/" 2>/dev/null || true
+            fi
+        done
+
+        if [ -f "$AGENTS_DIR/README.md" ]; then
+            cp -f "$AGENTS_DIR/README.md" "$REPO_AGENTS_DIR/README.md" 2>/dev/null || true
+        fi
+
+        print_msg "$GREEN" "✓ Repository agents updated"
+        log "INFO" "Repository agents updated at $REPO_AGENTS_DIR"
+    fi
 }
 
 # Commit to git