feat: 创建 LobsterDiary 模型，支持数据库存储日记

- 创建 LobsterDiary 模型
  * 关联龙虾（ForeignKey）
  * 日期、标题、内容
  * 分类（成才之路/工作记忆/技术笔记）
  * 标签（JSONField）
  * Embedding 字段（预留 RAG 支持）
  * 数据库索引优化

- 数据库迁移
  * 添加 LobsterDiary 表
  * 添加索引：lobster+date, category+date, date

- 导入脚本
  * 创建 import_diaries 管理命令
  * 导入飞行侠的成才之路日记（3 篇）

- 更新 API
  * /api/lobsters/<id>/diary/dates/ - 从数据库查询
  * /api/lobsters/<id>/diary/<date>/ - 从数据库读取

- PostgreSQL 配置模板
  * settings_postgresql.py
  * 准备好 PostgreSQL 迁移

技术栈：SQLite（当前） → PostgreSQL（未来）
RAG 支持：预留 embedding 字段，未来可扩展

🗄️ 日记正式进入数据库时代！

code/backend/api/views.py

@@ -7,7 +7,7 @@ from datetime import datetime
 import os
 from pathlib import Path
 import re
-from lobsters.models import Lobster
+from lobsters.models import Lobster, LobsterDiary
 
 @api_view(['GET'])
 def lobster_list(request):
@@ -121,38 +121,41 @@ def lobster_memory_detail(request, lobster_id, date):
 
 @api_view(['GET'])
 def lobster_diary_dates(request, lobster_id):
-    """获取龙虾有日记（成才之路）的日期列表"""
-    # 日记文件目录
-    diary_dir = Path(f'/home/node/.openclaw/workspace/flying-hero/memory/成才之路')
+    """获取龙虾有日记（成才之路）的日期列表 - 从数据库读取"""
+    try:
+        lobster = Lobster.objects.get(id=lobster_id)
+    except Lobster.DoesNotExist:
+        return Response({'error': '龙虾不存在'}, status=404)
     
-    # 获取所有日记文件
-    dates = []
-    if diary_dir.exists():
-        for file in diary_dir.glob('*.md'):
-            # 提取日期 (YYYY-MM-DD.md 或 YYYY-MM-DD-*.md)
-            match = re.match(r'(\d{4}-\d{2}-\d{2})(?:-.*)?\.md', file.name)
-            if match:
-                dates.append(match.group(1))
+    # 从数据库查询日记日期
+    diaries = LobsterDiary.objects.filter(
+        lobster=lobster,
+        category='chengcai'
+    ).values_list('date', flat=True).distinct()
     
-    dates = list(set(dates))  # 去重
-    dates.sort(reverse=True)
+    dates = [str(date) for date in sorted(diaries, reverse=True)]
     return Response({'dates': dates})
 
 @api_view(['GET'])
 def lobster_diary_detail(request, lobster_id, date):
-    """获取指定日期的日记内容（成才之路）"""
-    # 优先查找故事版，其次技术版，再其次普通版
-    diary_file = Path(f'/home/node/.openclaw/workspace/flying-hero/memory/成才之路/{date}-故事版.md')
-    if not diary_file.exists():
-        diary_file = Path(f'/home/node/.openclaw/workspace/flying-hero/memory/成才之路/{date}-技术版.md')
-    if not diary_file.exists():
-        diary_file = Path(f'/home/node/.openclaw/workspace/flying-hero/memory/成才之路/{date}.md')
+    """获取指定日期的日记内容（成才之路） - 从数据库读取"""
+    try:
+        lobster = Lobster.objects.get(id=lobster_id)
+    except Lobster.DoesNotExist:
+        return Response({'error': '龙虾不存在'}, status=404)
     
-    if not diary_file.exists():
-        return Response({'error': '该日期没有日记'}, status=404)
-    
-    content = diary_file.read_text(encoding='utf-8')
+    # 从数据库查询日记
+    try:
+        diary = LobsterDiary.objects.get(
+            lobster=lobster,
+            date=date,
+            category='chengcai'
+        )
         return Response({
-        'date': date,
-        'content': content
+            'date': str(diary.date),
+            'content': diary.content,
+            'title': diary.title,
+            'tags': diary.tags,
         })
+    except LobsterDiary.DoesNotExist:
+        return Response({'error': '该日期没有日记'}, status=404)

code/backend/backend/settings_postgresql.py

@@ -0,0 +1,33 @@
+"""
+PostgreSQL 数据库配置模板
+
+使用方法：
+1. 安装 PostgreSQL
+2. 创建数据库和用户
+3. 复制此文件为 settings_postgresql.py
+4. 修改密码
+5. 修改 backend/settings.py 中的 DATABASES 配置
+"""
+
+DATABASES = {
+    'default': {
+        'ENGINE': 'django.db.backends.postgresql',
+        'NAME': 'lobster_db',
+        'USER': 'lobster_user',
+        'PASSWORD': 'lobster2026',  # 请修改为你的密码
+        'HOST': 'localhost',
+        'PORT': '5432',
+        'CONN_MAX_AGE': 600,  # 连接持久化
+        'OPTIONS': {
+            'connect_timeout': 10,
+        },
+    }
+}
+
+# PostgreSQL 特定优化
+# 生产环境建议添加
+# CACHES = {
+#     'default': {
+#         'BACKEND': 'django.core.cache.backends.locmem.LocMem',
+#     }
+# }

code/backend/lobsters/management/commands/import_diaries.py

@@ -0,0 +1,84 @@
+#!/usr/bin/env python
+"""
+导入现有日记文件到数据库
+
+使用方法：
+python manage.py import_diaries
+"""
+
+from django.core.management.base import BaseCommand
+from pathlib import Path
+from datetime import datetime
+from lobsters.models import Lobster, LobsterDiary
+
+
+class Command(BaseCommand):
+    help = '导入现有日记文件到数据库'
+
+    def handle(self, *args, **kwargs):
+        self.stdout.write('🚀 开始导入日记...')
+        
+        # 获取飞行侠
+        try:
+            feixingxia = Lobster.objects.get(name='飞行侠')
+            self.stdout.write(f'✅ 找到龙虾：{feixingxia}')
+        except Lobster.DoesNotExist:
+            self.stdout.write(self.style.ERROR('❌ 未找到飞行侠'))
+            return
+        
+        # 日记目录
+        diary_dir = Path('/home/node/.openclaw/workspace/flying-hero/memory/成才之路')
+        
+        if not diary_dir.exists():
+            self.stdout.write(self.style.ERROR(f'❌ 日记目录不存在：{diary_dir}'))
+            return
+        
+        self.stdout.write(f'📂 扫描目录：{diary_dir}')
+        
+        # 导入日记
+        imported_count = 0
+        for file in diary_dir.glob('*.md'):
+            # 提取日期
+            filename = file.name
+            if filename.endswith('-故事版.md'):
+                date_str = filename.replace('-故事版.md', '')
+                category = 'chengcai'
+                title = f'成才之路 · 故事版 · {date_str}'
+            elif filename.endswith('-技术版.md'):
+                date_str = filename.replace('-技术版.md', '')
+                category = 'chengcai'
+                title = f'成才之路 · 技术版 · {date_str}'
+            else:
+                date_str = filename.replace('.md', '')
+                category = 'chengcai'
+                title = f'成才之路 · {date_str}'
+            
+            try:
+                date = datetime.strptime(date_str, '%Y-%m-%d').date()
+            except ValueError:
+                self.stdout.write(self.style.WARNING(f'⚠️  跳过无效日期文件：{filename}'))
+                continue
+            
+            # 读取内容
+            content = file.read_text(encoding='utf-8')
+            
+            # 创建或更新日记
+            diary, created = LobsterDiary.objects.update_or_create(
+                lobster=feixingxia,
+                date=date,
+                category=category,
+                defaults={
+                    'title': title,
+                    'content': content,
+                    'tags': ['成才之路', '成长日记'],
+                }
+            )
+            
+            if created:
+                self.stdout.write(self.style.SUCCESS(f'✅ 导入：{title}'))
+            else:
+                self.stdout.write(self.style.WARNING(f'🔄 更新：{title}'))
+            
+            imported_count += 1
+        
+        self.stdout.write(self.style.SUCCESS(f'\n🎉 导入完成！共导入 {imported_count} 篇日记'))

code/backend/lobsters/migrations/0002_lobster_workspace_lobsterdiary_and_more.py

@@ -0,0 +1,109 @@
+# Generated by Django 4.2 on 2026-04-03 09:37
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("lobsters", "0001_initial"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="lobster",
+            name="workspace",
+            field=models.CharField(
+                blank=True, default="", max_length=100, verbose_name="工作区"
+            ),
+        ),
+        migrations.CreateModel(
+            name="LobsterDiary",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("date", models.DateField(verbose_name="日期")),
+                ("title", models.CharField(max_length=200, verbose_name="标题")),
+                ("content", models.TextField(verbose_name="内容")),
+                (
+                    "category",
+                    models.CharField(
+                        choices=[
+                            ("chengcai", "成才之路"),
+                            ("memory", "工作记忆"),
+                            ("tech", "技术笔记"),
+                            ("other", "其他"),
+                        ],
+                        default="other",
+                        max_length=50,
+                        verbose_name="分类",
+                    ),
+                ),
+                (
+                    "tags",
+                    models.JSONField(blank=True, default=list, verbose_name="标签"),
+                ),
+                (
+                    "embedding",
+                    models.TextField(
+                        blank=True, null=True, verbose_name="文本向量 (JSON 格式)"
+                    ),
+                ),
+                (
+                    "embedding_model",
+                    models.CharField(
+                        blank=True,
+                        default="",
+                        max_length=50,
+                        verbose_name="Embedding 模型版本",
+                    ),
+                ),
+                (
+                    "created_at",
+                    models.DateTimeField(auto_now_add=True, verbose_name="创建时间"),
+                ),
+                (
+                    "updated_at",
+                    models.DateTimeField(auto_now=True, verbose_name="更新时间"),
+                ),
+                (
+                    "lobster",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="diaries",
+                        to="lobsters.lobster",
+                        verbose_name="龙虾",
+                    ),
+                ),
+            ],
+            options={
+                "verbose_name": "龙虾日记",
+                "verbose_name_plural": "龙虾日记",
+                "ordering": ["-date", "-created_at"],
+            },
+        ),
+        migrations.AddIndex(
+            model_name="lobsterdiary",
+            index=models.Index(
+                fields=["lobster", "date"], name="lobsters_lo_lobster_5895f8_idx"
+            ),
+        ),
+        migrations.AddIndex(
+            model_name="lobsterdiary",
+            index=models.Index(
+                fields=["category", "date"], name="lobsters_lo_categor_177677_idx"
+            ),
+        ),
+        migrations.AddIndex(
+            model_name="lobsterdiary",
+            index=models.Index(fields=["date"], name="lobsters_lo_date_d11f64_idx"),
+        ),
+    ]

code/backend/lobsters/models.py

@@ -1,4 +1,6 @@
 from django.db import models
+from django.utils import timezone
+
 
 class Lobster(models.Model):
     """龙虾模型"""
@@ -9,6 +11,7 @@ class Lobster(models.Model):
     container = models.CharField(max_length=100, verbose_name='容器')
     app_name = models.CharField(max_length=100, blank=True, default='', verbose_name='应用名称')
     app_id = models.CharField(max_length=50, blank=True, default='', verbose_name='应用 ID')
+    workspace = models.CharField(max_length=100, blank=True, default='', verbose_name='工作区')
     created_at = models.DateTimeField(auto_now_add=True, verbose_name='创建时间')
     updated_at = models.DateTimeField(auto_now=True, verbose_name='更新时间')
     
@@ -19,3 +22,73 @@ class Lobster(models.Model):
     
     def __str__(self):
         return f'{self.emoji} {self.name}'
+
+
+class LobsterDiary(models.Model):
+    """龙虾日记模型（支持 RAG）"""
+    
+    # 分类选择
+    CATEGORY_CHOICES = [
+        ('chengcai', '成才之路'),
+        ('memory', '工作记忆'),
+        ('tech', '技术笔记'),
+        ('other', '其他'),
+    ]
+    
+    # 关联龙虾
+    lobster = models.ForeignKey(
+        Lobster, 
+        on_delete=models.CASCADE, 
+        related_name='diaries',
+        verbose_name='龙虾'
+    )
+    
+    # 基本信息
+    date = models.DateField(verbose_name='日期')
+    title = models.CharField(max_length=200, verbose_name='标题')
+    content = models.TextField(verbose_name='内容')
+    
+    # 分类和标签（RAG 检索的关键元数据）
+    category = models.CharField(
+        max_length=50, 
+        choices=CATEGORY_CHOICES,
+        default='other',
+        verbose_name='分类'
+    )
+    tags = models.JSONField(default=list, blank=True, verbose_name='标签')
+    
+    # RAG 相关字段（预留）
+    embedding = models.TextField(
+        blank=True, 
+        null=True,
+        verbose_name='文本向量 (JSON 格式)'
+    )
+    embedding_model = models.CharField(
+        max_length=50, 
+        blank=True,
+        default='',
+        verbose_name='Embedding 模型版本'
+    )
+    
+    # 时间戳
+    created_at = models.DateTimeField(auto_now_add=True, verbose_name='创建时间')
+    updated_at = models.DateTimeField(auto_now=True, verbose_name='更新时间')
+    
+    class Meta:
+        verbose_name = '龙虾日记'
+        verbose_name_plural = '龙虾日记'
+        ordering = ['-date', '-created_at']
+        indexes = [
+            models.Index(fields=['lobster', 'date']),
+            models.Index(fields=['category', 'date']),
+            models.Index(fields=['date']),
+        ]
+    
+    def __str__(self):
+        return f'{self.lobster.emoji} {self.lobster.name} - {self.date} - {self.get_category_display()}'
+    
+    def get_content_preview(self, length=50):
+        """获取内容预览"""
+        if len(self.content) <= length:
+            return self.content
+        return self.content[:length] + '...'