feat(suggestions): full suggestion workflow with per-step notes

DB migration h5c6d7e8f9a0:
- Extends tdstatus enum: submitted → analyse → plan → implement →
  test → review → finished (+ wont_fix remains)
- New td_notes table: td_id FK (CASCADE), step, author, content, created_at

API:
- TDNote model + TDNoteCreate/TDNoteRead schemas
- TDRead includes notes[] (selectin loaded)
- New routes: GET/POST /technical-debt/{id}/notes/
- list_td status filter accepts str (all enum values)

Modal: new submissions use status="submitted" instead of "open"

UI Feedback page revamp:
- Visual step-by-step stepper (submitted→analyse→plan→implement→test→review→finished)
- Per-step notes: view all notes, add note inline
- Action buttons: advance to next step, won't fix
- Review step highlighted as awaiting original suggester confirmation
- Closed items (finished/wont_fix) shown with last 2 notes

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

api/models/technical_debt.py

@@ -1,19 +1,51 @@
 import enum
 import uuid
 
-from sqlalchemy import Enum, ForeignKey, String, Text
+from sqlalchemy import DateTime, Enum, ForeignKey, String, Text
 from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy.sql import func
 
 from api.models.base import Base, TimestampMixin, new_uuid
 
 
 class TDStatus(str, enum.Enum):
+    # Legacy general statuses
     open = "open"
     in_progress = "in_progress"
     resolved = "resolved"
     deferred = "deferred"
     wont_fix = "wont_fix"
+    # Dashboard-improvement workflow steps
+    submitted = "submitted"
+    analyse = "analyse"
+    plan = "plan"
+    implement = "implement"
+    test = "test"
+    review = "review"
+    finished = "finished"
+
+
+# Ordered workflow steps for dashboard-improvement suggestions
+SUGGESTION_STEPS = ["submitted", "analyse", "plan", "implement", "test", "review", "finished"]
+
+
+class TDNote(Base):
+    __tablename__ = "td_notes"
+
+    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=new_uuid)
+    td_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("technical_debt.id", ondelete="CASCADE"),
+        nullable=False, index=True,
+    )
+    step: Mapped[str] = mapped_column(String(30), nullable=False)
+    author: Mapped[str | None] = mapped_column(String(100), nullable=True)
+    content: Mapped[str] = mapped_column(Text, nullable=False)
+    created_at: Mapped[DateTime] = mapped_column(
+        DateTime(timezone=True), server_default=func.now(), nullable=False
+    )
+
+    td: Mapped["TechnicalDebt"] = relationship("TechnicalDebt", back_populates="notes")
 
 
 class TechnicalDebt(Base, TimestampMixin):
@@ -51,6 +83,10 @@ class TechnicalDebt(Base, TimestampMixin):
     domain: Mapped["Domain"] = relationship("Domain", lazy="selectin")  # noqa: F821
     topic: Mapped["Topic"] = relationship("Topic", lazy="selectin")  # noqa: F821
     workstream: Mapped["Workstream"] = relationship("Workstream", lazy="selectin")  # noqa: F821
+    notes: Mapped[list["TDNote"]] = relationship(
+        "TDNote", back_populates="td", lazy="selectin",
+        order_by="TDNote.created_at",
+    )
 
     @property
     def domain_slug(self) -> str:

api/routers/technical_debt.py

@@ -6,8 +6,8 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from api.database import get_session
 from api.models.domain import Domain
-from api.models.technical_debt import TDStatus, TechnicalDebt
-from api.schemas.technical_debt import TDCreate, TDRead, TDUpdate
+from api.models.technical_debt import TDNote, TDStatus, TechnicalDebt
+from api.schemas.technical_debt import TDCreate, TDNoteCreate, TDNoteRead, TDRead, TDUpdate
 
 router = APIRouter(prefix="/technical-debt", tags=["technical-debt"])
 
@@ -32,7 +32,7 @@ async def _resolve_domain_id(slug: str, session: AsyncSession) -> uuid.UUID:
 @router.get("/", response_model=list[TDRead])
 async def list_td(
     domain: str | None = None,
-    status: TDStatus | None = None,
+    status: str | None = None,         # str to accept both legacy and workflow values
     debt_type: str | None = None,
     severity: str | None = None,
     session: AsyncSession = Depends(get_session),
@@ -106,3 +106,35 @@ async def defer_td(
     await session.commit()
     await session.refresh(td)
     return td
+
+
+# ── Notes ─────────────────────────────────────────────────────────────────────
+
+@router.get("/{td_id}/notes/", response_model=list[TDNoteRead])
+async def list_notes(
+    td_id: uuid.UUID,
+    session: AsyncSession = Depends(get_session),
+) -> list[TDNote]:
+    td = await session.get(TechnicalDebt, td_id)
+    if td is None:
+        raise HTTPException(status_code=404, detail="Technical debt item not found")
+    result = await session.execute(
+        select(TDNote).where(TDNote.td_id == td_id).order_by(TDNote.created_at)
+    )
+    return list(result.scalars().all())
+
+
+@router.post("/{td_id}/notes/", response_model=TDNoteRead, status_code=status.HTTP_201_CREATED)
+async def add_note(
+    td_id: uuid.UUID,
+    body: TDNoteCreate,
+    session: AsyncSession = Depends(get_session),
+) -> TDNote:
+    td = await session.get(TechnicalDebt, td_id)
+    if td is None:
+        raise HTTPException(status_code=404, detail="Technical debt item not found")
+    note = TDNote(td_id=td_id, **body.model_dump())
+    session.add(note)
+    await session.commit()
+    await session.refresh(note)
+    return note

api/schemas/technical_debt.py

@@ -8,6 +8,23 @@ from api.models.technical_debt import TDStatus
 VALID_SEVERITIES = {"low", "medium", "high", "critical"}
 
 
+class TDNoteCreate(BaseModel):
+    step: str
+    author: str | None = None
+    content: str
+
+
+class TDNoteRead(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: uuid.UUID
+    td_id: uuid.UUID
+    step: str
+    author: str | None = None
+    content: str
+    created_at: datetime
+
+
 class TDCreate(BaseModel):
     td_id: str | None = None
     domain: str  # slug; router resolves to domain_id FK
@@ -47,3 +64,4 @@ class TDRead(BaseModel):
     workstream_id: uuid.UUID | None = None
     created_at: datetime
     updated_at: datetime
+    notes: list[TDNoteRead] = []