chore: add overnight helper scripts

- add morning report launcher\n- add overnight stop script\n- add watchdog health monitor script\n\nRefs #137

scripts/stop_overnight.sh

@@ -0,0 +1,76 @@
+#!/usr/bin/env bash
+# Stop The Ouroboros overnight app/watchdog/tmux session.
+
+set -euo pipefail
+
+LOG_DIR="${LOG_DIR:-data/overnight}"
+PID_FILE="$LOG_DIR/app.pid"
+WATCHDOG_PID_FILE="$LOG_DIR/watchdog.pid"
+TMUX_SESSION_PREFIX="${TMUX_SESSION_PREFIX:-ouroboros_overnight}"
+KILL_TIMEOUT="${KILL_TIMEOUT:-5}"
+
+stop_pid() {
+    local name="$1"
+    local pid="$2"
+
+    if [ -z "$pid" ]; then
+        echo "$name PID가 비어 있습니다."
+        return 1
+    fi
+
+    if ! kill -0 "$pid" 2>/dev/null; then
+        echo "$name 프로세스가 이미 종료됨 (pid=$pid)"
+        return 0
+    fi
+
+    kill "$pid" 2>/dev/null || true
+    for _ in $(seq 1 "$KILL_TIMEOUT"); do
+        if ! kill -0 "$pid" 2>/dev/null; then
+            echo "$name 종료됨 (pid=$pid)"
+            return 0
+        fi
+        sleep 1
+    done
+
+    kill -9 "$pid" 2>/dev/null || true
+    if ! kill -0 "$pid" 2>/dev/null; then
+        echo "$name 강제 종료됨 (pid=$pid)"
+        return 0
+    fi
+
+    echo "$name 종료 실패 (pid=$pid)"
+    return 1
+}
+
+status=0
+
+if [ -f "$WATCHDOG_PID_FILE" ]; then
+    watchdog_pid="$(cat "$WATCHDOG_PID_FILE" || true)"
+    stop_pid "watchdog" "$watchdog_pid" || status=1
+    rm -f "$WATCHDOG_PID_FILE"
+else
+    echo "watchdog pid 파일 없음: $WATCHDOG_PID_FILE"
+fi
+
+if [ -f "$PID_FILE" ]; then
+    app_pid="$(cat "$PID_FILE" || true)"
+    stop_pid "app" "$app_pid" || status=1
+    rm -f "$PID_FILE"
+else
+    echo "app pid 파일 없음: $PID_FILE"
+fi
+
+if command -v tmux >/dev/null 2>&1; then
+    sessions="$(tmux ls 2>/dev/null | awk -F: -v p="$TMUX_SESSION_PREFIX" '$1 ~ "^" p "_" {print $1}')"
+    if [ -n "$sessions" ]; then
+        while IFS= read -r s; do
+            [ -z "$s" ] && continue
+            tmux kill-session -t "$s" 2>/dev/null || true
+            echo "tmux 세션 종료: $s"
+        done <<< "$sessions"
+    else
+        echo "종료할 tmux 세션 없음 (prefix=${TMUX_SESSION_PREFIX}_)"
+    fi
+fi
+
+exit "$status"