feat(state-hub): add Extension Points and Technical Debt tracking

New entity types (DB tables, API routers, Pydantic schemas, Alembic
migration a3f1c2d4e5b6):
- extension_points: ep_id, domain, title, ep_type, status, priority,
  location, description, topic_id, workstream_id
- technical_debt: td_id, domain, title, debt_type, severity, status,
  location, description, topic_id, workstream_id

MCP server: 6 new tools — register_extension_point, list_extension_points,
update_ep_status, register_technical_debt, list_technical_debt,
update_td_status (each write emits a progress_event)

Dashboard: two new pages (extensions.md, techdept.md) with KPI sidebar,
charts, urgent-items section, and filterable card lists. Both added to
nav in observablehq.config.js.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

api/schemas/__init__.py

@@ -4,6 +4,8 @@ from api.schemas.task import TaskCreate, TaskUpdate, TaskRead
 from api.schemas.decision import DecisionCreate, DecisionUpdate, DecisionRead
 from api.schemas.progress_event import ProgressEventCreate, ProgressEventRead
 from api.schemas.state import StateSummary, Totals, TopicTotals, WorkstreamTotals, TaskTotals, DecisionTotals
+from api.schemas.extension_point import EPCreate, EPUpdate, EPRead
+from api.schemas.technical_debt import TDCreate, TDUpdate, TDRead
 
 __all__ = [
     "TopicCreate", "TopicUpdate", "TopicRead", "TopicWithWorkstreams",
@@ -12,4 +14,6 @@ __all__ = [
     "DecisionCreate", "DecisionUpdate", "DecisionRead",
     "ProgressEventCreate", "ProgressEventRead",
     "StateSummary", "Totals", "TopicTotals", "WorkstreamTotals", "TaskTotals", "DecisionTotals",
+    "EPCreate", "EPUpdate", "EPRead",
+    "TDCreate", "TDUpdate", "TDRead",
 ]

api/schemas/extension_point.py

@@ -0,0 +1,53 @@
+import uuid
+from datetime import datetime
+
+from pydantic import BaseModel, ConfigDict
+
+from api.models.extension_point import EPStatus
+
+VALID_DOMAINS = {
+    "custodian", "railiance", "markitect",
+    "coulomb_social", "personhood", "foerster_capabilities",
+}
+VALID_PRIORITIES = {"low", "medium", "high", "critical"}
+
+
+class EPCreate(BaseModel):
+    ep_id: str | None = None
+    domain: str
+    title: str
+    description: str | None = None
+    location: str | None = None
+    ep_type: str = "other"
+    status: EPStatus = EPStatus.open
+    priority: str = "medium"
+    topic_id: uuid.UUID | None = None
+    workstream_id: uuid.UUID | None = None
+
+
+class EPUpdate(BaseModel):
+    title: str | None = None
+    description: str | None = None
+    location: str | None = None
+    ep_type: str | None = None
+    status: EPStatus | None = None
+    priority: str | None = None
+    workstream_id: uuid.UUID | None = None
+
+
+class EPRead(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: uuid.UUID
+    ep_id: str | None = None
+    domain: str
+    title: str
+    description: str | None = None
+    location: str | None = None
+    ep_type: str
+    status: EPStatus
+    priority: str
+    topic_id: uuid.UUID | None = None
+    workstream_id: uuid.UUID | None = None
+    created_at: datetime
+    updated_at: datetime

api/schemas/technical_debt.py

@@ -0,0 +1,49 @@
+import uuid
+from datetime import datetime
+
+from pydantic import BaseModel, ConfigDict
+
+from api.models.technical_debt import TDStatus
+
+VALID_SEVERITIES = {"low", "medium", "high", "critical"}
+
+
+class TDCreate(BaseModel):
+    td_id: str | None = None
+    domain: str
+    title: str
+    description: str | None = None
+    location: str | None = None
+    debt_type: str = "other"
+    severity: str = "medium"
+    status: TDStatus = TDStatus.open
+    topic_id: uuid.UUID | None = None
+    workstream_id: uuid.UUID | None = None
+
+
+class TDUpdate(BaseModel):
+    title: str | None = None
+    description: str | None = None
+    location: str | None = None
+    debt_type: str | None = None
+    severity: str | None = None
+    status: TDStatus | None = None
+    workstream_id: uuid.UUID | None = None
+
+
+class TDRead(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: uuid.UUID
+    td_id: str | None = None
+    domain: str
+    title: str
+    description: str | None = None
+    location: str | None = None
+    debt_type: str
+    severity: str
+    status: TDStatus
+    topic_id: uuid.UUID | None = None
+    workstream_id: uuid.UUID | None = None
+    created_at: datetime
+    updated_at: datetime