fix: remove obsolete slot-based concurrency mechanism

The session-counting approach (PR #65) now properly handles agent
concurrency limits. Remove the broken slot-based mechanism:

- Remove acquire_agent_slot() and release_agent_slot() functions
- Remove AGENT_COUNT_FILE and AGENT_LOCK_FILE variables
- Remove unused run_with_limit() function
- Remove release-slot.sh script
- Update cmd_delegate to use fire-and-forget without slot management

Both cmd_start and cmd_delegate now use count_active_dev_sessions()
for concurrency checking.

skills/kugetsu/scripts/kugetsu

@@ -9,44 +9,6 @@ INDEX_FILE="$KUGETSU_DIR/index.json"
 NOTIFICATIONS_FILE="$KUGETSU_DIR/notifications.json"
 LOGS_DIR="$KUGETSU_DIR/logs"
 MAX_CONCURRENT_AGENTS="${MAX_CONCURRENT_AGENTS:-3}"
-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"
-}
 
 count_active_dev_sessions() {
     local count=0
@@ -63,17 +25,6 @@ count_active_dev_sessions() {
     echo "$count"
 }
 
-run_with_limit() {
-    local log_file="$1"
-    shift
-    local cmd=("$@")
-    (
-        "${cmd[@]}" >> "$log_file" 2>&1
-        release_agent_slot
-    ) &
-    disown
-}
-
 usage() {
     cat << 'EOF'
 kugetsu - OpenCode Session Manager (Issue-Driven)
@@ -148,8 +99,6 @@ EOF
 
 ensure_dirs() {
     mkdir -p "$SESSIONS_DIR"
-    [ -f "$AGENT_COUNT_FILE" ] || echo 0 > "$AGENT_COUNT_FILE"
-
 }
 
 ensure_worktree_dir() {
@@ -569,11 +518,7 @@ cmd_delegate() {
     
     mkdir -p "$LOGS_DIR"
     local log_file="$LOGS_DIR/delegate-$(date +%s).log"
-    if ! acquire_agent_slot; then
-        echo "Error: Max concurrent agents ($MAX_CONCURRENT_AGENTS) reached. Try again later." >&2
-        exit 1
-    fi
-    nohup sh -c "opencode run '$message' --continue --session '$pm_session' >> '$log_file' 2>&1; ~/.kugetsu/release-slot.sh" > /dev/null 2>&1 &
+    nohup sh -c "opencode run '$message' --continue --session '$pm_session' >> '$log_file' 2>&1" > /dev/null 2>&1 &
     disown
     echo "Delegated to PM agent (logged to $(basename "$log_file"))"
 }

skills/kugetsu/scripts/release-slot.sh

@@ -1,11 +0,0 @@
-#!/bin/bash
-KUGETSU_DIR="${KUGETSU_DIR:-$HOME/.kugetsu}"
-AGENT_COUNT_FILE="$KUGETSU_DIR/.agent_count"
-AGENT_LOCK_FILE="$KUGETSU_DIR/.agent_lock"
-(
-    flock -w 1 200 || true
-    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"