Finish CUST-WP-0011 and implement STATE-WP-0061 suggestion backlog.

Add persisted Suggestion entities with WSJF ranking, relevance bumps,
REST/MCP write surfaces, /suggestions dashboard page, and daily triage
digest integration. Document the cluster operating model, archive the
completed migration workplan, and seed WARDEN-WP-0012 routing scenarios.

api/schemas/suggestion.py

@@ -0,0 +1,96 @@
+import uuid
+from datetime import datetime
+
+from pydantic import BaseModel, ConfigDict, Field
+
+from api.models.suggestion import SuggestionStage
+
+
+class SuggestionNoteRead(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: uuid.UUID
+    suggestion_id: uuid.UUID
+    stage: str
+    author: str | None = None
+    content: str
+    created_at: datetime
+
+
+class SuggestionRead(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: uuid.UUID
+    domain_id: uuid.UUID
+    domain_slug: str = ""
+    topic_id: uuid.UUID | None = None
+    workplan_id: uuid.UUID | None = None
+    title: str
+    description: str | None = None
+    origin: str | None = None
+    origin_ref: str | None = None
+    stage: SuggestionStage
+    relevance: int
+    relevance_events: int
+    last_requested_at: datetime | None = None
+    base_value: float
+    job_size: float
+    relevance_weight: float
+    promoted_task_id: uuid.UUID | None = None
+    cost_of_delay: float | None = None
+    wsjf: float | None = None
+    created_at: datetime
+    updated_at: datetime
+    notes: list[SuggestionNoteRead] = Field(default_factory=list)
+
+
+class SuggestionCreate(BaseModel):
+    domain: str
+    title: str
+    description: str | None = None
+    topic_id: uuid.UUID | None = None
+    workplan_id: uuid.UUID | None = None
+    origin: str | None = None
+    origin_ref: str | None = None
+    base_value: float = 3.0
+    job_size: float = 3.0
+    relevance_weight: float = 1.0
+
+
+class SuggestionVet(BaseModel):
+    author: str | None = None
+    note: str
+    base_value: float | None = None
+    job_size: float | None = None
+    relevance_weight: float | None = None
+    workplan_id: uuid.UUID | None = None
+
+
+class SuggestionDecline(BaseModel):
+    author: str | None = None
+    note: str
+
+
+class SuggestionPromote(BaseModel):
+    author: str | None = None
+    note: str | None = None
+    task_title: str | None = None
+    task_description: str | None = None
+    task_priority: str = "medium"
+    task_status: str = "wait"
+
+
+class SuggestionBumpRelevance(BaseModel):
+    reason: str | None = None
+    author: str | None = None
+
+
+class RankedSuggestionDigest(BaseModel):
+    id: uuid.UUID
+    title: str
+    stage: SuggestionStage
+    domain_slug: str
+    origin_ref: str | None = None
+    relevance: int
+    wsjf: float
+    last_requested_at: datetime | None = None