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/decision.py

@@ -25,8 +25,8 @@ class Decision(Base, TimestampMixin):
     __tablename__ = "decisions"
     __table_args__ = (
         CheckConstraint(
-            "topic_id IS NOT NULL OR workstream_id IS NOT NULL",
-            name="ck_decisions_topic_or_workstream",
+            "topic_id IS NOT NULL OR workplan_id IS NOT NULL",
+            name="ck_decisions_topic_or_workplan",
         ),
     )
 
@@ -36,8 +36,8 @@ class Decision(Base, TimestampMixin):
     topic_id: Mapped[uuid.UUID | None] = mapped_column(
         UUID(as_uuid=True), ForeignKey("topics.id", ondelete="RESTRICT"), nullable=True, index=True
     )
-    workstream_id: Mapped[uuid.UUID | None] = mapped_column(
-        UUID(as_uuid=True), ForeignKey("workstreams.id", ondelete="RESTRICT"), nullable=True, index=True
+    workplan_id: Mapped[uuid.UUID | None] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("workplans.id", ondelete="RESTRICT"), nullable=True, index=True
     )
     title: Mapped[str] = mapped_column(String(255), nullable=False)
     description: Mapped[str | None] = mapped_column(Text, nullable=True)
@@ -57,7 +57,7 @@ class Decision(Base, TimestampMixin):
     )
 
     topic: Mapped["Topic | None"] = relationship("Topic", back_populates="decisions")  # noqa: F821
-    workstream: Mapped["Workstream | None"] = relationship("Workstream", back_populates="decisions")  # noqa: F821
+    workplan: Mapped["Workplan | None"] = relationship("Workplan", back_populates="decisions")  # noqa: F821
     progress_events: Mapped[list["ProgressEvent"]] = relationship(  # noqa: F821
         "ProgressEvent", back_populates="decision", lazy="selectin"
     )