feat: add task type hierarchy with subtypes (issue/meeting/support/maintenance/research/review/story/test)

app/models/models.py

@@ -6,10 +6,16 @@ import enum
 
 
 class IssueType(str, enum.Enum):
-    TASK = "task"
-    STORY = "story"
-    TEST = "test"
-    RESOLUTION = "resolution"  # 决议案 - 用于 Agent 僵局提交
+    MEETING = meeting
+    SUPPORT = support
+    ISSUE = issue
+    MAINTENANCE = maintenance
+    RESEARCH = research
+    REVIEW = review
+    STORY = story
+    TEST = test
+    RESOLUTION = resolution  # 决议案 - 用于 Agent 僵局提交
+    TASK = task  # legacy generic type
 
 
 class IssueStatus(str, enum.Enum):
@@ -33,7 +39,8 @@ class Issue(Base):
     id = Column(Integer, primary_key=True, index=True)
     title = Column(String(255), nullable=False)
     description = Column(Text, nullable=True)
-    issue_type = Column(Enum(IssueType), default=IssueType.TASK)
+    issue_type = Column(String(32), default=IssueType.ISSUE.value)
+    issue_subtype = Column(String(64), nullable=True)
     status = Column(Enum(IssueStatus), default=IssueStatus.OPEN)
     priority = Column(Enum(IssuePriority), default=IssuePriority.MEDIUM)