feat(classification-spine): implement STATE-WP-0065 repo-anchored model

Replace the ad-hoc coordination-domain spine with the Repo Classification
Standard: 14 market domains, classification columns on managed_repos, and
workplans anchored by repo_id (topic_id optional).

- Add Alembic migration d8e9f0a1b2c3 with data backfill and workstream→workplan rename
- Add api/classification.py validation and register-from-classification tooling
- Expose workplan-first REST/MCP surface with legacy workstream aliases
- Add C-24 consistency rule and legacy domain frontmatter mapping
- Update dashboard repos page with category/capability/stake filters
- Update orientation docs; mark STATE-WP-0065 finished

api/models/task.py

@@ -30,8 +30,8 @@ class Task(Base, TimestampMixin):
     id: Mapped[uuid.UUID] = mapped_column(
         UUID(as_uuid=True), primary_key=True, default=new_uuid
     )
-    workstream_id: Mapped[uuid.UUID] = mapped_column(
-        UUID(as_uuid=True), ForeignKey("workstreams.id", ondelete="RESTRICT"), nullable=False, index=True
+    workplan_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("workplans.id", ondelete="RESTRICT"), nullable=False, index=True
     )
     title: Mapped[str] = mapped_column(String(255), nullable=False)
     description: Mapped[str | None] = mapped_column(Text, nullable=True)
@@ -50,7 +50,7 @@ class Task(Base, TimestampMixin):
         UUID(as_uuid=True), ForeignKey("tasks.id", ondelete="SET NULL"), nullable=True
     )
 
-    workstream: Mapped["Workstream"] = relationship("Workstream", back_populates="tasks")  # noqa: F821
+    workplan: Mapped["Workplan"] = relationship("Workplan", back_populates="tasks")  # noqa: F821
     subtasks: Mapped[list["Task"]] = relationship(
         "Task", foreign_keys=[parent_task_id], lazy="selectin"
     )