feat: task numbers (TEA-1, TEA-2...) + project key_prefix

- Project: key_prefix (auto from name), task_counter
- Task: number (auto-increment per project)
- API returns 'key' field (e.g. TEA-1)
- Migration numbers existing tasks

alembic/versions/864b0ce5d657_add_task_number_and_project_key_prefix.py

@@ -0,0 +1,55 @@
+"""add task number and project key_prefix
+
+Revision ID: 864b0ce5d657
+Revises: 59dd2d9071fd
+Create Date: 2026-02-15 19:27:43.338390
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+revision: str = '864b0ce5d657'
+down_revision: Union[str, None] = '59dd2d9071fd'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # Add as nullable first
+    op.add_column('projects', sa.Column('key_prefix', sa.String(length=10), nullable=True))
+    op.add_column('projects', sa.Column('task_counter', sa.Integer(), nullable=True))
+    op.add_column('tasks', sa.Column('number', sa.Integer(), nullable=True))
+
+    # Fill defaults
+    op.execute("UPDATE projects SET key_prefix = UPPER(LEFT(REGEXP_REPLACE(name, '[^a-zA-Z]', '', 'g'), 3)) WHERE key_prefix IS NULL")
+    op.execute("UPDATE projects SET key_prefix = 'PRJ' WHERE key_prefix IS NULL OR key_prefix = ''")
+    op.execute("UPDATE projects SET task_counter = 0 WHERE task_counter IS NULL")
+    op.execute("UPDATE tasks SET number = 0 WHERE number IS NULL")
+
+    # Number existing tasks sequentially per project
+    op.execute("""
+        WITH numbered AS (
+            SELECT id, ROW_NUMBER() OVER (PARTITION BY project_id ORDER BY created_at) as rn
+            FROM tasks
+        )
+        UPDATE tasks SET number = numbered.rn FROM numbered WHERE tasks.id = numbered.id
+    """)
+    # Update project counters
+    op.execute("""
+        UPDATE projects SET task_counter = COALESCE(
+            (SELECT MAX(number) FROM tasks WHERE tasks.project_id = projects.id), 0
+        )
+    """)
+
+    # Make NOT NULL
+    op.alter_column('projects', 'key_prefix', nullable=False)
+    op.alter_column('projects', 'task_counter', nullable=False, server_default='0')
+    op.alter_column('tasks', 'number', nullable=False, server_default='0')
+
+
+def downgrade() -> None:
+    op.drop_column('tasks', 'number')
+    op.drop_column('projects', 'task_counter')
+    op.drop_column('projects', 'key_prefix')

src/tracker/api/projects.py

@@ -17,6 +17,7 @@ class ProjectCreate(BaseModel):
     name: str
     slug: str
     description: str | None = None
+    key_prefix: str | None = None  # auto-generated from name if not provided
     git_repo: str | None = None
 
 
@@ -31,6 +32,8 @@ class ProjectOut(BaseModel):
     name: str
     slug: str
     description: str | None
+    key_prefix: str
+    task_counter: int
     git_repo: str | None
 
     model_config = {"from_attributes": True}
@@ -44,7 +47,12 @@ async def list_projects(db: AsyncSession = Depends(get_db)):
 
 @router.post("/", response_model=ProjectOut, status_code=201)
 async def create_project(data: ProjectCreate, db: AsyncSession = Depends(get_db)):
-    project = Project(**data.model_dump())
+    dump = data.model_dump()
+    # Auto-generate key_prefix from name (first 3 chars, uppercase)
+    if not dump.get("key_prefix"):
+        prefix = "".join(c for c in data.name.upper() if c.isalpha())[:3]
+        dump["key_prefix"] = prefix or "PRJ"
+    project = Project(**dump)
     db.add(project)
     await db.commit()
     await db.refresh(project)

src/tracker/api/tasks.py

@@ -9,7 +9,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import selectinload
 
 from tracker.database import get_db
-from tracker.models import Task
+from tracker.models import Task, Project
 
 router = APIRouter(prefix="/tasks", tags=["tasks"])
 
@@ -46,11 +46,33 @@ class TaskOut(BaseModel):
     requires_pr: bool
     pr_url: str | None
     assigned_agent_id: uuid.UUID | None
+    number: int
+    key: str | None = None  # e.g. "TEA-1"
     position: int
 
     model_config = {"from_attributes": True}
 
 
+async def _enrich_tasks(tasks: list[Task], db: AsyncSession) -> list[TaskOut]:
+    """Add key (e.g. TEA-1) to task outputs."""
+    if not tasks:
+        return []
+    # Collect project ids
+    project_ids = {t.project_id for t in tasks}
+    projects = {}
+    for pid in project_ids:
+        p = await db.get(Project, pid)
+        if p:
+            projects[p.id] = p.key_prefix
+    result = []
+    for t in tasks:
+        out = TaskOut.model_validate(t)
+        prefix = projects.get(t.project_id, "???")
+        out.key = f"{prefix}-{t.number}" if t.number else None
+        result.append(out)
+    return result
+
+
 @router.get("/", response_model=list[TaskOut])
 async def list_tasks(
     project_id: uuid.UUID | None = None,
@@ -63,16 +85,27 @@ async def list_tasks(
     if status:
         q = q.where(Task.status == status)
     result = await db.execute(q)
-    return result.scalars().all()
+    tasks = list(result.scalars().all())
+    return await _enrich_tasks(tasks, db)
 
 
 @router.post("/", response_model=TaskOut, status_code=201)
 async def create_task(data: TaskCreate, db: AsyncSession = Depends(get_db)):
-    task = Task(**data.model_dump())
+    # Get project and increment counter
+    project = await db.get(Project, data.project_id)
+    if not project:
+        raise HTTPException(404, "Project not found")
+    project.task_counter += 1
+    number = project.task_counter
+
+    task = Task(**data.model_dump(), number=number)
     db.add(task)
     await db.commit()
     await db.refresh(task)
-    return task
+    # Attach key
+    task_out = TaskOut.model_validate(task)
+    task_out.key = f"{project.key_prefix}-{number}"
+    return task_out
 
 
 @router.get("/{task_id}", response_model=TaskOut)
@@ -80,7 +113,8 @@ async def get_task(task_id: uuid.UUID, db: AsyncSession = Depends(get_db)):
     task = await db.get(Task, task_id)
     if not task:
         raise HTTPException(404, "Task not found")
-    return task
+    enriched = await _enrich_tasks([task], db)
+    return enriched[0]
 
 
 @router.patch("/{task_id}", response_model=TaskOut)

src/tracker/models/project.py

@@ -3,7 +3,7 @@
 import uuid
 from typing import TYPE_CHECKING
 
-from sqlalchemy import String, Text
+from sqlalchemy import Integer, String, Text
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from tracker.models.base import Base
@@ -19,6 +19,8 @@ class Project(Base):
     name: Mapped[str] = mapped_column(String(255), nullable=False)
     slug: Mapped[str] = mapped_column(String(255), unique=True, nullable=False)
     description: Mapped[str | None] = mapped_column(Text)
+    key_prefix: Mapped[str] = mapped_column(String(10), nullable=False, default="PRJ")  # e.g. "TEA", "DIC"
+    task_counter: Mapped[int] = mapped_column(Integer, default=0)  # auto-increment for task numbers
     git_repo: Mapped[str | None] = mapped_column(String(500))
 
     tasks: Mapped[list["Task"]] = relationship(back_populates="project", cascade="all, delete-orphan")

src/tracker/models/task.py

@@ -26,6 +26,7 @@ class Task(Base):
     requires_pr: Mapped[bool] = mapped_column(Boolean, default=False)
     pr_url: Mapped[str | None] = mapped_column(String(500))
     assigned_agent_id: Mapped[uuid.UUID | None] = mapped_column(UUID(as_uuid=True), ForeignKey("agents.id"))
+    number: Mapped[int] = mapped_column(Integer, nullable=False, default=0)  # project-scoped sequential number (TEA-1, TEA-2...)
     position: Mapped[int] = mapped_column(Integer, default=0)  # ordering within column
 
     project: Mapped["Project"] = relationship(back_populates="tasks")