feat: add goal management module (long-term goals with phases, milestones, reviews)

Backend:
- Goal model: title, description, status (active/paused/completed/abandoned),
  progress (auto-computed from milestones), target_date, category, color, icon
- GoalStep model: unified phase/milestone with parent nesting
- GoalReview model: periodic reflection with rating
- goal_tasks M2M: link existing tasks to goals
- /api/goals CRUD + steps CRUD + reviews + task linking + status toggle
- Progress auto-calculated from milestone completion ratio

Frontend:
- GoalPage: card grid with progress bars, status filter
- GoalDetailPage: step tree (phases > milestones), reviews, linked tasks
- GoalDialog: create/edit form with color/icon picker
- Goal navigation in AppHeader
- useGoalStore: full Pinia store for all goal operations

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

api/app/models/__init__.py

@@ -4,9 +4,11 @@ from app.models.tag import Tag, task_tags
 from app.models.user_settings import UserSettings
 from app.models.habit import HabitGroup, Habit, HabitCheckin
 from app.models.anniversary import AnniversaryCategory, Anniversary
+from app.models.goal import Goal, GoalStep, GoalReview, goal_tasks
 
 __all__ = [
     "Task", "Category", "Tag", "task_tags", "UserSettings",
     "HabitGroup", "Habit", "HabitCheckin",
     "AnniversaryCategory", "Anniversary",
+    "Goal", "GoalStep", "GoalReview", "goal_tasks",
 ]

api/app/models/goal.py

@@ -0,0 +1,80 @@
+from sqlalchemy import Column, Integer, String, Text, Date, DateTime, ForeignKey, Table, desc
+from sqlalchemy.orm import relationship
+from app.database import Base
+from app.utils.datetime import utcnow
+
+
+# 目标-任务关联表（多对多）
+goal_tasks = Table(
+    "goal_tasks",
+    Base.metadata,
+    Column("goal_id", Integer, ForeignKey("goals.id"), primary_key=True),
+    Column("task_id", Integer, ForeignKey("tasks.id"), primary_key=True),
+)
+
+
+class Goal(Base):
+    """长期目标模型"""
+    __tablename__ = "goals"
+
+    id = Column(Integer, primary_key=True, index=True)
+    title = Column(String(200), nullable=False)
+    description = Column(Text, nullable=True)
+    status = Column(String(20), default="active")  # active/paused/completed/abandoned
+    progress = Column(Integer, default=0)  # 0-100，从里程碑自动计算
+    target_date = Column(Date, nullable=True)
+    completed_at = Column(DateTime, nullable=True)
+    category_id = Column(Integer, ForeignKey("categories.id"), nullable=True)
+    color = Column(String(20), default="#FFB7C5")
+    icon = Column(String(50), default="flag")
+    sort_order = Column(Integer, default=0)
+    created_at = Column(DateTime, default=utcnow)
+    updated_at = Column(DateTime, default=utcnow, onupdate=utcnow)
+
+    # 关联关系
+    category = relationship("Category")
+    steps = relationship(
+        "GoalStep", back_populates="goal",
+        cascade="all, delete-orphan",
+        order_by="GoalStep.sort_order",
+    )
+    reviews = relationship(
+        "GoalReview", back_populates="goal",
+        cascade="all, delete-orphan",
+        order_by=lambda: desc(GoalReview.created_at),
+    )
+    tasks = relationship("Task", secondary=goal_tasks, back_populates="goals")
+
+
+class GoalStep(Base):
+    """目标阶段/里程碑模型（step_type 区分类型）"""
+    __tablename__ = "goal_steps"
+
+    id = Column(Integer, primary_key=True, index=True)
+    goal_id = Column(Integer, ForeignKey("goals.id"), nullable=False)
+    parent_id = Column(Integer, ForeignKey("goal_steps.id"), nullable=True)
+    title = Column(String(200), nullable=False)
+    step_type = Column(String(20), nullable=False)  # "phase" | "milestone"
+    status = Column(String(20), default="pending")  # pending/in_progress/completed
+    target_date = Column(Date, nullable=True)
+    reached_at = Column(DateTime, nullable=True)
+    sort_order = Column(Integer, default=0)
+    created_at = Column(DateTime, default=utcnow)
+
+    # 关联关系
+    goal = relationship("Goal", back_populates="steps")
+    parent = relationship("GoalStep", remote_side=[id], backref="children")
+
+
+class GoalReview(Base):
+    """目标复盘记录模型"""
+    __tablename__ = "goal_reviews"
+
+    id = Column(Integer, primary_key=True, index=True)
+    goal_id = Column(Integer, ForeignKey("goals.id"), nullable=False)
+    content = Column(Text, nullable=False)
+    rating = Column(Integer, nullable=True)  # 1-5 自评
+    created_at = Column(DateTime, default=utcnow)
+
+    # 关联关系
+    goal = relationship("Goal", back_populates="reviews")

api/app/models/task.py

@@ -21,3 +21,4 @@ class Task(Base):
     # 关联关系
     category = relationship("Category", back_populates="tasks")
     tags = relationship("Tag", secondary="task_tags", back_populates="tasks")
+    goals = relationship("Goal", secondary="goal_tasks", back_populates="tasks")