feat(kugetsu): increase MAX_CONCURRENT_AGENTS from 3 to 5

Based on testing, 5 concurrent agents provides better throughput
without overwhelming system resources.

skills/kugetsu/scripts/kugetsu

@@ -7,6 +7,58 @@ WORKTREES_DIR="$KUGETSU_DIR/worktrees"
 REPOS_CONFIG="$KUGETSU_DIR/repos.json"
 INDEX_FILE="$KUGETSU_DIR/index.json"
 NOTIFICATIONS_FILE="$KUGETSU_DIR/notifications.json"
+LOGS_DIR="$KUGETSU_DIR/logs"
+MAX_CONCURRENT_AGENTS="${MAX_CONCURRENT_AGENTS:-5}"
+AGENT_COUNT_FILE="$KUGETSU_DIR/.agent_count"
+AGENT_LOCK_FILE="$KUGETSU_DIR/.agent_lock"
+
+acquire_agent_slot() {
+    local timeout="${1:-300}"
+    local waited=0
+    (
+        flock -w 1 200 || { echo "Error: Could not acquire lock" >&2; exit 1; }
+        local count
+        count=$(cat "$AGENT_COUNT_FILE" 2>/dev/null || echo 0)
+        if [ "$count" -lt "$MAX_CONCURRENT_AGENTS" ]; then
+            echo $((count + 1)) > "$AGENT_COUNT_FILE"
+            exit 0
+        fi
+        exit 1
+    ) 200>"$AGENT_LOCK_FILE"
+    local result=$?
+    if [ $result -ne 0 ]; then
+        local count
+        count=$(cat "$AGENT_COUNT_FILE" 2>/dev/null || echo 0)
+        if [ $waited -ge $timeout ]; then
+            echo "Error: Timeout waiting for agent slot (max: $MAX_CONCURRENT_AGENTS, current: $count)" >&2
+        fi
+        return 1
+    fi
+    return 0
+}
+
+release_agent_slot() {
+    (
+        flock -w 1 200 || true
+        local count
+        count=$(cat "$AGENT_COUNT_FILE" 2>/dev/null || echo 0)
+        if [ "$count" -gt 0 ]; then
+            echo $((count - 1)) > "$AGENT_COUNT_FILE"
+        fi
+    ) 200>"$AGENT_LOCK_FILE"
+}
+
+run_with_limit() {
+    local log_file="$1"
+    shift
+    local cmd=("$@")
+    (
+        "${cmd[@]}" >> "$log_file" 2>&1
+        release_agent_slot
+    ) &
+    disown
+}
+>>>>>>> Stashed changes
 
 usage() {
     cat << 'EOF'