Fixing errors and danger zone

CLAUDE.md

@@ -87,7 +87,7 @@ The business domain, independent of the auth/RBAC skeleton:
 - **`app/services/scope_import.py`** is a separate, manually-triggered bulk
   importer: reads an uploaded `.xlsx` of third-party scopes, upserting by
   `product_number` (→ `AugmentedPart.sku`) and creating `ScopeModel`,
-  `ScopeInfo`, up to three `AttachmentPoint`s, and up to two `Fit`s per row
+  `ScopeInfo`, up to two `AttachmentPoint`s, and up to two `Fit`s per row
   (see the module docstring for the full column mapping).
 - **`app/services/scope_guide.py`** assembles the `/scopes` page: one row per
   Scope-type `AugmentedPart`, one column per other `PartType`, each cell

FitGuide.md

@@ -21,3 +21,4 @@
 - Models
 - Colours
 - Part Types
+- Notes

alembic/versions/1b99be8a9b1e_add_fits_tables.py

@@ -31,10 +31,16 @@ def upgrade() -> None:
             nullable=False,
         ),
         sa.Column(
-            "created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.func.now(),
+            nullable=False,
         ),
         sa.Column(
-            "updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False
+            "updated_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.func.now(),
+            nullable=False,
         ),
         sa.ForeignKeyConstraint(
             ["attachment_point_a_id"], ["attachment_points.id"], ondelete="CASCADE"
@@ -59,7 +65,10 @@ def upgrade() -> None:
         sa.Column("username", sa.String(length=255), nullable=False),
         sa.Column("body", sa.Text(), nullable=False),
         sa.Column(
-            "created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.func.now(),
+            nullable=False,
         ),
         sa.ForeignKeyConstraint(["fit_id"], ["fits.id"], ondelete="CASCADE"),
         sa.ForeignKeyConstraint(["user_id"], ["users.id"], ondelete="SET NULL"),

alembic/versions/a3f7c19b2d40_add_objective_lens_diameter_to_scope_infos.py

@@ -0,0 +1,28 @@
+"""add_objective_lens_diameter_to_scope_infos
+
+Revision ID: a3f7c19b2d40
+Revises: 8012c00b0c04
+Create Date: 2026-08-04 00:00:00.000000
+"""
+
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision: str = "a3f7c19b2d40"
+down_revision: Union[str, None] = "8012c00b0c04"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "scope_infos",
+        sa.Column("objective_lens_diameter_mm", sa.Float(), nullable=True),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("scope_infos", "objective_lens_diameter_mm")

app/api/fits.py

@@ -67,9 +67,7 @@ async def create_fit(
     if ap_a is None or ap_b is None:
         raise HTTPException(status_code=404, detail="Attachment point not found")
     if ap_a.augmented_part_id == ap_b.augmented_part_id:
-        raise HTTPException(
-            status_code=422, detail="a part cannot fit itself"
-        )
+        raise HTTPException(status_code=422, detail="a part cannot fit itself")
     existing = await fit_crud.get_by_attachment_points(db, ap_a, ap_b)
     if existing is not None:
         raise HTTPException(status_code=409, detail="Fit already exists")

app/core/database.py

@@ -35,6 +35,7 @@ if engine.sync_engine.dialect.name == "sqlite":
         cursor.execute("PRAGMA busy_timeout=5000")
         cursor.close()
 
+
 AsyncSessionLocal = async_sessionmaker(
     engine,
     class_=AsyncSession,

app/crud/attachment_point.py

@@ -2,6 +2,7 @@ from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.models.attachment_point import AttachmentPoint
+from app.models.attachment_point_name import AttachmentPointName
 
 _RELATIONSHIPS = [
     "attachment_point_name",
@@ -27,6 +28,24 @@ async def list_for_augmented_part(
     return list(result.scalars().all())
 
 
+async def list_by_augmented_parts_and_name(
+    db: AsyncSession, augmented_part_ids: list[int], name: str
+) -> list[AttachmentPoint]:
+    """AttachmentPoints named ``name`` for the given augmented parts, fetched in
+    one query."""
+    if not augmented_part_ids:
+        return []
+    result = await db.execute(
+        select(AttachmentPoint)
+        .join(AttachmentPoint.attachment_point_name)
+        .where(
+            AttachmentPoint.augmented_part_id.in_(augmented_part_ids),
+            AttachmentPointName.name == name,
+        )
+    )
+    return list(result.scalars().all())
+
+
 async def list_all(
     db: AsyncSession, skip: int = 0, limit: int = 100
 ) -> list[AttachmentPoint]:

app/crud/role.py

@@ -23,9 +23,7 @@ async def get_default(db: AsyncSession) -> Role | None:
 
 async def set_default(db: AsyncSession, role: Role) -> Role:
     """Make ``role`` the sole default, clearing the flag on every other role."""
-    await db.execute(
-        sa_update(Role).where(Role.id != role.id).values(is_default=False)
-    )
+    await db.execute(sa_update(Role).where(Role.id != role.id).values(is_default=False))
     role.is_default = True
     await db.commit()
     await db.refresh(role)

app/crud/scope_info.py

@@ -24,9 +24,7 @@ async def list_by_augmented_parts(
     if not augmented_part_ids:
         return []
     result = await db.execute(
-        select(ScopeInfo).where(
-            ScopeInfo.augmented_part_id.in_(augmented_part_ids)
-        )
+        select(ScopeInfo).where(ScopeInfo.augmented_part_id.in_(augmented_part_ids))
     )
     return list(result.scalars().all())
 
@@ -38,6 +36,7 @@ async def create(
     magnification_min: float | None = None,
     magnification_max: float | None = None,
     model_suffix: str | None = None,
+    objective_lens_diameter_mm: float | None = None,
     objective_thread_pitch: str | None = None,
 ) -> ScopeInfo:
     info = ScopeInfo(
@@ -45,6 +44,7 @@ async def create(
         magnification_min=magnification_min,
         magnification_max=magnification_max,
         model_suffix=model_suffix,
+        objective_lens_diameter_mm=objective_lens_diameter_mm,
         objective_thread_pitch=objective_thread_pitch,
     )
     db.add(info)

app/models/scope_info.py

@@ -27,6 +27,11 @@ class ScopeInfo(Base):
     model_suffix: Mapped[str | None] = mapped_column(
         String, nullable=True, default=None
     )
+    # The lens diameter is a descriptive attribute (the "50" in "3-18x50"), not a
+    # connection dimension — it has no AttachmentPoint.
+    objective_lens_diameter_mm: Mapped[float | None] = mapped_column(
+        Float, nullable=True, default=None
+    )
     # Kept as the raw string from the sheet (e.g. "0.75", "1/16") so no precision
     # or notation is lost; the parsed thread lives on its own AttachmentPoint.
     objective_thread_pitch: Mapped[str | None] = mapped_column(

app/schemas/scope_info.py

@@ -5,6 +5,7 @@ class ScopeInfoBase(BaseModel):
     magnification_min: float | None = None
     magnification_max: float | None = None
     model_suffix: str | None = None
+    objective_lens_diameter_mm: float | None = None
     objective_thread_pitch: str | None = None
 
 

app/services/danger_zone.py

@@ -0,0 +1,54 @@
+"""Irreversible bulk-delete of all domain (parts/taxonomy/fit) data.
+
+Leaves users, roles/permissions, refresh tokens, the audit log, and the
+ImportedPartConfig (OData connection settings) untouched.
+"""
+
+from sqlalchemy import delete
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.associations import augmented_part_imported_parts
+from app.models.attachment_point import AttachmentPoint
+from app.models.attachment_point_name import AttachmentPointName
+from app.models.augmented_part import AugmentedPart, AugmentedPartNote
+from app.models.clamp_connection import ClampConnection
+from app.models.fit import Fit, FitNote
+from app.models.imported_part import ImportedPart
+from app.models.iso_thread import IsoThread
+from app.models.manufacturer import Manufacturer
+from app.models.scope_info import ScopeInfo
+from app.models.scope_model import ScopeModel
+from app.models.static_connection import StaticConnection
+from app.models.unc_thread import UncThread
+
+# Children before the RESTRICT-protected reference tables they point to.
+_TARGETS = [
+    ("Fit notes", FitNote),
+    ("Fits", Fit),
+    ("Augmented part notes", AugmentedPartNote),
+    ("Scope info", ScopeInfo),
+    ("Attachment points", AttachmentPoint),
+    ("Augmented part / imported part links", augmented_part_imported_parts),
+    ("Augmented parts", AugmentedPart),
+    ("Imported parts", ImportedPart),
+    ("Scope models", ScopeModel),
+    ("Attachment point names", AttachmentPointName),
+    ("ISO threads", IsoThread),
+    ("UNC threads", UncThread),
+    ("Clamp connections", ClampConnection),
+    ("Static connections", StaticConnection),
+    ("Manufacturers", Manufacturer),
+]
+
+
+async def purge_domain_data(db: AsyncSession) -> dict[str, int]:
+    """Delete every row from every domain table, in FK-safe order.
+
+    Returns a label -> rows-deleted map for reporting/audit purposes.
+    """
+    counts: dict[str, int] = {}
+    for label, target in _TARGETS:
+        result = await db.execute(delete(target))
+        counts[label] = result.rowcount or 0
+    await db.commit()
+    return counts

app/services/fit_matching.py

@@ -142,9 +142,7 @@ async def _reconcile(
             for own_ap in own_points:
                 for other_ap in points_by_part.get(other_id, []):
                     if attachment_points_match(own_ap, other_ap):
-                        candidate_pairs.add(
-                            _canonical_pair(own_ap.id, other_ap.id)
-                        )
+                        candidate_pairs.add(_canonical_pair(own_ap.id, other_ap.id))
 
     result = RecomputeResult()
 
@@ -171,7 +169,9 @@ async def _reconcile(
     return result
 
 
-async def recompute_for_part(db: AsyncSession, augmented_part_id: int) -> RecomputeResult:
+async def recompute_for_part(
+    db: AsyncSession, augmented_part_id: int
+) -> RecomputeResult:
     """Reconcile Possible fits involving this part against the current algorithm.
 
     Creates Possible fits for newly-matching attachment point pairs, and removes

app/services/scope_guide.py

@@ -7,6 +7,7 @@ the parts of that type that fit the row's scope.
 
 from sqlalchemy.ext.asyncio import AsyncSession
 
+from app.crud import attachment_point as attachment_point_crud
 from app.crud import augmented_part as augmented_part_crud
 from app.crud import fit as fit_crud
 from app.crud import part_type as part_type_crud
@@ -14,6 +15,7 @@ from app.crud import scope_info as scope_info_crud
 from app.models.fit import FitLabel
 
 SCOPE_TYPE_NAME = "Scope"
+OBJECTIVE_ATTACHMENT_POINT_NAME = "Objective"
 
 # "exact" outranks "possible" when the same part fits a scope via several fits.
 _LABEL_RANK = {FitLabel.EXACT.value: 2, FitLabel.POSSIBLE.value: 1}
@@ -43,6 +45,7 @@ async def build(
                 {
                     "scope": AugmentedPart,
                     "info": ScopeInfo | None,
+                    "objective_attachment_point": AttachmentPoint | None,
                     "cells": {part_type_id: [{"part": AugmentedPart, "label": str}]},
                 },
                 ...,
@@ -50,9 +53,7 @@ async def build(
         }
     """
     part_types = await part_type_crud.list_all(db, limit=1000)
-    scope_type = next(
-        (pt for pt in part_types if pt.name == SCOPE_TYPE_NAME), None
-    )
+    scope_type = next((pt for pt in part_types if pt.name == SCOPE_TYPE_NAME), None)
     column_types = [
         pt for pt in part_types if scope_type is None or pt.id != scope_type.id
     ]
@@ -87,6 +88,13 @@ async def build(
         p.id: p for p in await augmented_part_crud.get_many(db, list(other_ids))
     }
 
+    objective_aps = {
+        ap.augmented_part_id: ap
+        for ap in await attachment_point_crud.list_by_augmented_parts_and_name(
+            db, list(scope_ids), OBJECTIVE_ATTACHMENT_POINT_NAME
+        )
+    }
+
     infos = {
         info.augmented_part_id: info
         for info in await scope_info_crud.list_by_augmented_parts(db, list(scope_ids))
@@ -94,9 +102,7 @@ async def build(
 
     # cell_map[scope_id][type_id][other_part_id] -> {"part", "label"}, dedup'd so a
     # part appears once per cell, keeping its strongest fit label.
-    cell_map: dict[int, dict[int, dict[int, dict]]] = {
-        sid: {} for sid in scope_ids
-    }
+    cell_map: dict[int, dict[int, dict[int, dict]]] = {sid: {} for sid in scope_ids}
     for fit in fits:
         scope_id, other_id = _scope_and_other(fit, scope_ids)
         if scope_id is None:
@@ -121,7 +127,12 @@ async def build(
         if fits_part_type_id is not None and fits_part_type_id not in cells:
             continue  # scope has no fit for the required accessory type
         rows.append(
-            {"scope": scope, "info": infos.get(scope.id), "cells": cells}
+            {
+                "scope": scope,
+                "info": infos.get(scope.id),
+                "objective_attachment_point": objective_aps.get(scope.id),
+                "cells": cells,
+            }
         )
 
     return {"column_types": column_types, "rows": rows}

app/services/scope_import.py

@@ -2,7 +2,7 @@
 
 The spreadsheet describes parts of PartType "Scope". Each row maps onto an
 AugmentedPart (keyed on ``product_number`` → ``sku``, so re-importing upserts),
-a ScopeModel, a ScopeInfo record for the scope-specific fields, up to three
+a ScopeModel, a ScopeInfo record for the scope-specific fields, up to two
 attachment points, and up to two Fits against other parts.
 
 Column → destination
@@ -14,9 +14,9 @@ model_suffix                        → ScopeInfo.model_suffix (+ description)
 sub_part_type                       → SubPartType (get-or-create under "Scope")
 product_number                      → AugmentedPart.sku  (also the upsert / fit-lookup key)
 magnification_min / _max            → ScopeInfo
+objective_lens_diameter_mm          → ScopeInfo (descriptive only, no attachment point)
 objective_thread_pitch              → ScopeInfo
 ocular_outer_diameter_mm            → StaticConnection + AttachmentPoint "Ocular"
-objective_lens_outside_diameter_mm  → StaticConnection + AttachmentPoint "Objective"
 objective_thread                    → ISO/UNC thread + AttachmentPoint "Objective"
 ocular_fit                          → Fit: scope's Ocular AP ↔ referenced part's first AP
 objective_fit                       → Fit: scope's Objective AP ↔ referenced part's first AP
@@ -68,7 +68,7 @@ EXPECTED_COLUMNS = [
     "model",
     "magnification_min",
     "magnification_max",
-    "objective_lens_outside_diameter_mm",
+    "objective_lens_diameter_mm",
     "model_suffix",
     "sub_part_type",
     "product_number",
@@ -140,15 +140,11 @@ def parse_workbook(data: bytes) -> list[dict]:
         wb.close()
 
 
-async def _static_ap(
-    db: AsyncSession, *, augmented_part_id: int, label: str, od_mm: float
-):
+async def _static_ap(db: AsyncSession, *, augmented_part_id: int, label: str, od_mm: float):
     """Create an attachment point carrying a StaticConnection for ``od_mm``."""
     sc = await static_connection_crud.get_by_od_mm(db, od_mm)
     if sc is None:
-        sc = await static_connection_crud.create(
-            db, od_mm=od_mm, od_in=od_mm / MM_PER_INCH
-        )
+        sc = await static_connection_crud.create(db, od_mm=od_mm, od_in=od_mm / MM_PER_INCH)
     apn = await apn_crud.get_by_name(db, label)
     if apn is None:
         apn = await apn_crud.create(db, name=label)
@@ -160,9 +156,7 @@ async def _static_ap(
     )
 
 
-async def _thread_ap(
-    db: AsyncSession, *, augmented_part_id: int, label: str, spec: str
-):
+async def _thread_ap(db: AsyncSession, *, augmented_part_id: int, label: str, spec: str):
     """Create an attachment point for a parsed ISO/UNC thread, or None."""
     parsed = _parse_thread_attribute(spec)
     if parsed is None:
@@ -206,8 +200,7 @@ async def _link_fit(
     """Create a POSSIBLE fit from the scope's AP to the referenced part's first AP."""
     if scope_ap is None:
         messages.append(
-            f"{scope_role}_fit '{target_sku}' skipped: scope has no "
-            f"{scope_role} attachment point"
+            f"{scope_role}_fit '{target_sku}' skipped: scope has no {scope_role} attachment point"
         )
         return
     target = await augmented_part_crud.get_by_sku(db, target_sku)
@@ -220,16 +213,13 @@ async def _link_fit(
     target_aps = await attachment_point_crud.list_for_augmented_part(db, target.id)
     if not target_aps:
         messages.append(
-            f"{scope_role}_fit '{target_sku}' skipped: referenced part has no "
-            "attachment points"
+            f"{scope_role}_fit '{target_sku}' skipped: referenced part has no attachment points"
         )
         return
     target_ap = target_aps[0]
     existing = await fit_crud.get_by_attachment_points(db, scope_ap, target_ap)
     if existing is None:
-        await fit_crud.create(
-            db, ap_a=scope_ap, ap_b=target_ap, label=FitLabel.POSSIBLE
-        )
+        await fit_crud.create(db, ap_a=scope_ap, ap_b=target_ap, label=FitLabel.POSSIBLE)
 
 
 async def import_scopes(db: AsyncSession, rows: list[dict]) -> ScopeImportResult:
@@ -250,7 +240,9 @@ async def import_scopes(db: AsyncSession, rows: list[dict]) -> ScopeImportResult
     for offset, row in enumerate(rows):
         # +2: 1-based, and the header occupies row 1.
         row_num = offset + 2
-        product_number = _text(row.get("product_number")) or _text(row.get("model"))
+        model_suffix = _text(row.get("model_suffix"))
+        default_product_number = f"{_text(row.get('model'))} {row.get('magnification_min')}-{row.get('magnification_max')}x{row.get('objective_lens_diameter_mm')} {row.get('model_suffix')}".strip()
+        product_number = _text(row.get("product_number")) or default_product_number
         result = ScopeImportRowResult(
             row=row_num, product_number=product_number, status="skipped", messages=[]
         )
@@ -271,9 +263,7 @@ async def import_scopes(db: AsyncSession, rows: list[dict]) -> ScopeImportResult
 
             manufacturer = await manufacturer_crud.get_by_name(db, manufacturer_name)
             if manufacturer is None:
-                manufacturer = await manufacturer_crud.create(
-                    db, name=manufacturer_name, url=""
-                )
+                manufacturer = await manufacturer_crud.create(db, name=manufacturer_name, url="")
 
             model_name = _text(row.get("model"))
             url = _text(row.get("url"))
@@ -330,14 +320,13 @@ async def import_scopes(db: AsyncSession, rows: list[dict]) -> ScopeImportResult
                 magnification_min=_num(row.get("magnification_min")),
                 magnification_max=_num(row.get("magnification_max")),
                 model_suffix=model_suffix,
+                objective_lens_diameter_mm=_num(row.get("objective_lens_diameter_mm")),
                 objective_thread_pitch=_text(row.get("objective_thread_pitch")),
             )
 
             # Rebuild attachment points from scratch so re-imports stay idempotent
             # (cascades delete any fits that referenced the old points).
-            for old_ap in await attachment_point_crud.list_for_augmented_part(
-                db, part.id
-            ):
+            for old_ap in await attachment_point_crud.list_for_augmented_part(db, part.id):
                 await attachment_point_crud.delete(db, old_ap)
 
             ocular_ap = None
@@ -350,34 +339,22 @@ async def import_scopes(db: AsyncSession, rows: list[dict]) -> ScopeImportResult
                     od_mm=ocular_od,
                 )
 
-            objective_static_ap = None
-            objective_od = _num(row.get("objective_lens_outside_diameter_mm"))
-            if objective_od is not None:
-                objective_static_ap = await _static_ap(
-                    db,
-                    augmented_part_id=part.id,
-                    label=OBJECTIVE_LABEL,
-                    od_mm=objective_od,
-                )
-
+            # The objective attachment point comes from the thread alone — the
+            # lens diameter is a descriptive attribute, not a connection.
             objective_thread_spec = _text(row.get("objective_thread"))
-            objective_thread_ap = None
+            objective_ap = None
             if objective_thread_spec:
-                objective_thread_ap = await _thread_ap(
+                objective_ap = await _thread_ap(
                     db,
                     augmented_part_id=part.id,
                     label=OBJECTIVE_LABEL,
                     spec=objective_thread_spec,
                 )
-                if objective_thread_ap is None:
+                if objective_ap is None:
                     result.messages.append(
-                        f"could not parse objective_thread "
-                        f"'{objective_thread_spec}'"
+                        f"could not parse objective_thread '{objective_thread_spec}'"
                     )
 
-            # For objective_fit prefer the lens-OD point, falling back to the thread.
-            objective_ap = objective_static_ap or objective_thread_ap
-
             staged.append((row, ocular_ap, objective_ap, part.id, result))
             row_results.append(result)
         except Exception as exc:  # noqa: BLE001 - report, don't abort the batch

app/templates/_connection_macros.html

@@ -0,0 +1,17 @@
+{%- macro connection_spec(ap) -%}
+  {%- if ap.iso_thread -%}
+    M{{ ap.iso_thread.diameter_mm }}×{{ ap.iso_thread.pitch_mm }}
+  {%- elif ap.unc_thread -%}
+    {{ ap.unc_thread.diameter_fraction }}-{{ ap.unc_thread.tpi }} {{ ap.unc_thread.series.value }}
+  {%- elif ap.clamp_connection -%}
+    {%- if ap.clamp_connection.min_mm is not none -%}
+      {{ ap.clamp_connection.min_mm }}–{{ ap.clamp_connection.max_mm }} mm
+    {%- else -%}
+      {{ ap.clamp_connection.min_in }}–{{ ap.clamp_connection.max_in }} in
+    {%- endif -%}
+  {%- elif ap.static_connection -%}
+    {{ ap.static_connection.od_mm }} mm OD
+  {%- else -%}
+    —
+  {%- endif -%}
+{%- endmacro -%}

app/templates/_nav.html

@@ -145,6 +145,9 @@
         {% if su or "audit_log:read" in p %}
           <a href="/admin/audit-log">{{ icon("list-checks") }} Audit Log</a>
         {% endif %}
+        {% if su %}
+          <a href="/admin/danger-zone">{{ icon("alert-circle") }} Danger Zone</a>
+        {% endif %}
       </div>
     </div>
     {% endif %}

app/templates/_scopes_table_card.html

@@ -1,11 +1,18 @@
+{% from "_connection_macros.html" import connection_spec %}
 {%- macro mag(v) -%}{{ v | int if v == v | int else v | round(1) }}{%- endmacro -%}
-{%- macro magnification(info) -%}
+{%- macro magnification_range(info) -%}
   {%- if info and info.magnification_min is not none and info.magnification_max is not none -%}
-    {{ mag(info.magnification_min) }}–{{ mag(info.magnification_max) }}×
+    {{ mag(info.magnification_min) }}-{{ mag(info.magnification_max) }}
   {%- elif info and info.magnification_min is not none -%}
-    {{ mag(info.magnification_min) }}×
+    {{ mag(info.magnification_min) }}
   {%- elif info and info.magnification_max is not none -%}
-    {{ mag(info.magnification_max) }}×
+    {{ mag(info.magnification_max) }}
+  {%- endif -%}
+{%- endmacro -%}
+{%- macro magnification(info) -%}
+  {%- set range = magnification_range(info) -%}
+  {%- if range -%}
+    {{ range }}x{% if info.objective_lens_diameter_mm is not none %}{{ mag(info.objective_lens_diameter_mm) }}{% endif %}
   {%- else -%}
     <span class="muted">—</span>
   {%- endif -%}
@@ -39,7 +46,9 @@
           <td>{{ scope.sub_part_type.name if scope.sub_part_type else "—" }}</td>
           <td>{{ magnification(info) }}</td>
           <td>
-            {% if info and info.objective_thread_pitch %}
+            {% if row.objective_attachment_point %}
+              <code>{{ connection_spec(row.objective_attachment_point) }}</code>
+            {% elif info and info.objective_thread_pitch %}
               {{ info.objective_thread_pitch }}
             {% else %}<span class="muted">—</span>{% endif %}
           </td>

app/templates/admin/_danger_zone_result.html

@@ -0,0 +1,14 @@
+{% if total %}
+<p style="color:var(--color-danger,#c00)">
+  Purge complete: {{ total }} row(s) deleted.
+</p>
+<ul class="muted">
+  {% for label, n in counts.items() %}
+  {% if n %}
+  <li>{{ label }}: {{ n }}</li>
+  {% endif %}
+  {% endfor %}
+</ul>
+{% else %}
+<p class="muted">Nothing to purge — the database was already clean.</p>
+{% endif %}

app/templates/admin/augmented_part_detail.html

@@ -44,6 +44,12 @@
           {% else %}—{% endif %}
         </dd>
         <dt>Model suffix</dt><dd>{{ scope_info.model_suffix or "—" }}</dd>
+        <dt>Objective lens diameter</dt>
+        <dd>
+          {% if scope_info.objective_lens_diameter_mm is not none %}
+            {{ scope_info.objective_lens_diameter_mm }} mm
+          {% else %}—{% endif %}
+        </dd>
         <dt>Objective thread</dt><dd>{{ scope_info.objective_thread_pitch or "—" }}</dd>
       </dl>
     </div>

app/templates/admin/danger_zone.html

@@ -0,0 +1,32 @@
+{% extends "base.html" %}
+{% block title %}Danger Zone · {{ app_name }}{% endblock %}
+{% block body %}
+{% include "_nav.html" %}
+<main class="container">
+  <h1>Danger Zone</h1>
+
+  <div class="card" style="border: 1px solid var(--color-danger, #c00)">
+    <h2>Purge database</h2>
+    <p>
+      Permanently deletes every part, attachment point, fit, and imported
+      part in the database — manufacturers, scope models, ISO/UNC threads,
+      clamp/static connections, attachment point names, augmented parts,
+      scope info, attachment points, fits, fit notes, and imported parts.
+    </p>
+    <p>
+      <strong>Not</strong> deleted: users, roles &amp; permissions, refresh
+      tokens, the audit log, the OData connection configuration, and part
+      taxonomy (part colours, part types, sub part types).
+    </p>
+    <p class="muted">This cannot be undone. Take a database backup first if you might need this data again.</p>
+    <button class="btn btn-danger"
+            hx-post="/admin/danger-zone/purge"
+            hx-target="#purge-result"
+            hx-swap="innerHTML"
+            hx-confirm="This will PERMANENTLY delete all parts, taxonomy, attachment points, fits, and imported parts. Users and the OData configuration are kept. This cannot be undone. Continue?">
+      Purge all part/fit data
+    </button>
+    <div id="purge-result" style="margin-top:1rem"></div>
+  </div>
+</main>
+{% endblock %}

app/web/admin.py

@@ -43,6 +43,7 @@ from app.models.fit import FitLabel
 from app.models.unc_thread import UncSeries
 from app.models.user import User
 from app.services import augmented_part_sync as augmented_part_sync_service
+from app.services import danger_zone as danger_zone_service
 from app.services import fit_matching as fit_matching_service
 from app.services import jobs
 from app.services import odata as odata_service
@@ -131,6 +132,16 @@ def web_require(*perms: str):
     return checker
 
 
+async def web_require_superuser(user: User = Depends(get_current_web_user)) -> User:
+    """Web dependency: superusers only, no permission-string bypass."""
+    if not user.is_superuser:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="You do not have access to this page.",
+        )
+    return user
+
+
 async def _role_perm_ctx(db: AsyncSession) -> dict:
     all_perms = await role_crud.list_permissions(db)
     scopes = sorted({p.name.split(":")[0] for p in all_perms})
@@ -3598,3 +3609,45 @@ async def audit_log_page(
         "admin/audit_log.html",
         {"user": user, "entries": await audit_crud.list_recent(db)},
     )
+
+
+# --- Danger Zone ---------------------------------------------------------------
+
+
+@router.get("/danger-zone", response_class=HTMLResponse)
+async def danger_zone_page(
+    request: Request,
+    user: User = Depends(web_require_superuser),
+):
+    return templates.TemplateResponse(
+        request,
+        "admin/danger_zone.html",
+        {"user": user},
+    )
+
+
+@router.post("/danger-zone/purge", response_class=HTMLResponse)
+async def purge_database(
+    request: Request,
+    db: AsyncSession = Depends(get_db),
+    actor: User = Depends(web_require_superuser),
+):
+    counts = await danger_zone_service.purge_domain_data(db)
+    total = sum(counts.values())
+    breakdown = ", ".join(f"{label} {n}" for label, n in counts.items() if n)
+    await audit_crud.log(
+        db,
+        actor=actor,
+        action="delete",
+        resource_type="Database",
+        resource_id=None,
+        description=(
+            f"Purged all domain data via Danger Zone ({total} row(s) deleted"
+            + (f": {breakdown})" if breakdown else ")")
+        ),
+    )
+    return templates.TemplateResponse(
+        request,
+        "admin/_danger_zone_result.html",
+        {"total": total, "counts": counts},
+    )

tests/test_danger_zone.py

@@ -0,0 +1,158 @@
+import pytest
+
+from app.crud import audit as audit_crud
+from app.models.attachment_point import AttachmentPoint
+from app.models.attachment_point_name import AttachmentPointName
+from app.models.augmented_part import AugmentedPart, AugmentedPartNote
+from app.models.clamp_connection import ClampConnection
+from app.models.fit import Fit, FitLabel, FitNote
+from app.models.imported_part import ImportedPart
+from app.models.imported_part_config import ImportedPartConfig
+from app.models.iso_thread import IsoThread
+from app.models.manufacturer import Manufacturer
+from app.models.part_colour import PartColour
+from app.models.part_type import PartType
+from app.models.scope_info import ScopeInfo
+from app.models.scope_model import ScopeModel
+from app.models.static_connection import StaticConnection
+from app.models.sub_part_type import SubPartType
+from app.models.unc_thread import UncSeries, UncThread
+
+
+async def _seed_domain_data(db):
+    manufacturer = Manufacturer(name="Acme", url="https://acme.test")
+    colour = PartColour(name="Black")
+    scope_t = PartType(name="Scope")
+    cover_t = PartType(name="Flip Cover")
+    apn = AttachmentPointName(name="Objective")
+    db.add_all([manufacturer, colour, scope_t, cover_t, apn])
+    await db.flush()
+
+    sub_t = SubPartType(name="Riflescope", part_type_id=scope_t.id)
+    scope_model = ScopeModel(name="Alpha", manufacturer_id=manufacturer.id)
+    iso = IsoThread(diameter_mm=52.0, pitch_mm=0.75)
+    unc = UncThread(diameter_fraction="1/4", tpi=20, series=UncSeries.UNC)
+    clamp = ClampConnection(min_mm=25.0, max_mm=30.0)
+    static = StaticConnection(od_mm=50.0, od_in=1.97)
+    db.add_all([sub_t, scope_model, iso, unc, clamp, static])
+    await db.flush()
+
+    scope = AugmentedPart(
+        description="Alpha 3-18x50",
+        sku="ALP-318",
+        colour_id=colour.id,
+        manufacturer_id=manufacturer.id,
+        part_type_id=scope_t.id,
+        scope_model_id=scope_model.id,
+        sub_part_type_id=sub_t.id,
+    )
+    cover = AugmentedPart(
+        description="Flip cover 50mm",
+        colour_id=colour.id,
+        manufacturer_id=manufacturer.id,
+        part_type_id=cover_t.id,
+    )
+    db.add_all([scope, cover])
+    await db.flush()
+
+    db.add(AugmentedPartNote(augmented_part_id=scope.id, username="tester", body="note"))
+    db.add(ScopeInfo(augmented_part_id=scope.id, magnification_min=3, magnification_max=18))
+
+    ap_s = AttachmentPoint(
+        augmented_part_id=scope.id,
+        attachment_point_name_id=apn.id,
+        iso_thread_id=iso.id,
+    )
+    ap_c = AttachmentPoint(
+        augmented_part_id=cover.id,
+        attachment_point_name_id=apn.id,
+        iso_thread_id=iso.id,
+    )
+    db.add_all([ap_s, ap_c])
+    await db.flush()
+
+    fit = Fit(
+        attachment_point_a_id=ap_s.id,
+        attachment_point_b_id=ap_c.id,
+        augmented_part_a_id=scope.id,
+        augmented_part_b_id=cover.id,
+        label=FitLabel.POSSIBLE,
+    )
+    db.add(fit)
+    await db.flush()
+    db.add(FitNote(fit_id=fit.id, username="tester", body="fits fine"))
+
+    imported = ImportedPart(InventoryID="INV-1", Description="Alpha 3-18x50")
+    db.add(imported)
+
+    config = ImportedPartConfig(id=1, odata_url="https://example.test/odata", username="svc")
+    db.add(config)
+
+    await db.commit()
+
+
+async def _web_login(client, email, password="secret123"):
+    resp = await client.post("/login", data={"email": email, "password": password})
+    assert resp.status_code == 303
+
+
+@pytest.mark.asyncio
+async def test_non_superuser_forbidden(client, seeded, make_user):
+    # "admin" role holds every permission but is not a superuser.
+    await make_user("admin@example.com", role_ids=[seeded["roles"]["admin"].id])
+    await _web_login(client, "admin@example.com")
+
+    assert (await client.get("/admin/danger-zone")).status_code == 403
+    assert (await client.post("/admin/danger-zone/purge")).status_code == 403
+
+
+@pytest.mark.asyncio
+async def test_purge_wipes_domain_data_but_keeps_users_and_odata_config(
+    client, seeded, make_user, db_sessionmaker
+):
+    async with db_sessionmaker() as db:
+        await _seed_domain_data(db)
+
+    await make_user("root@example.com", is_superuser=True)
+    await _web_login(client, "root@example.com")
+
+    assert (await client.get("/admin/danger-zone")).status_code == 200
+
+    resp = await client.post("/admin/danger-zone/purge")
+    assert resp.status_code == 200
+    assert "Purge complete" in resp.text
+
+    async with db_sessionmaker() as db:
+        for Model in (
+            AugmentedPart,
+            AugmentedPartNote,
+            ScopeInfo,
+            AttachmentPoint,
+            Fit,
+            FitNote,
+            ImportedPart,
+            ScopeModel,
+            AttachmentPointName,
+            IsoThread,
+            UncThread,
+            ClampConnection,
+            StaticConnection,
+            Manufacturer,
+        ):
+            rows = (await db.execute(Model.__table__.select())).all()
+            assert rows == [], f"{Model.__name__} should be empty after purge"
+
+        # Kept: users, RBAC, the OData connection config, and part taxonomy.
+        from app.crud import user as user_crud
+
+        assert await user_crud.get_by_email(db, "root@example.com") is not None
+        config = await db.get(ImportedPartConfig, 1)
+        assert config is not None
+        assert config.odata_url == "https://example.test/odata"
+
+        for Model in (PartColour, PartType, SubPartType):
+            rows = (await db.execute(Model.__table__.select())).all()
+            assert rows != [], f"{Model.__name__} should survive the purge"
+
+        entries = await audit_crud.list_recent(db)
+        assert any("Purged all domain data" in e.description for e in entries)

tests/test_fit_matching.py

@@ -34,20 +34,40 @@ def test_same_label_never_matches_even_with_identical_threads():
 
 
 def test_unc_thread_exact_match():
-    a = _ap(1, 1, unc_thread=UncThread(diameter_fraction="1/4", tpi=20, series=UncSeries.UNC))
-    b = _ap(2, 2, unc_thread=UncThread(diameter_fraction="1/4", tpi=20, series=UncSeries.UNC))
+    a = _ap(
+        1,
+        1,
+        unc_thread=UncThread(diameter_fraction="1/4", tpi=20, series=UncSeries.UNC),
+    )
+    b = _ap(
+        2,
+        2,
+        unc_thread=UncThread(diameter_fraction="1/4", tpi=20, series=UncSeries.UNC),
+    )
     assert attachment_points_match(a, b)
 
 
 def test_unc_thread_series_mismatch():
-    a = _ap(1, 1, unc_thread=UncThread(diameter_fraction="1/4", tpi=20, series=UncSeries.UNC))
-    b = _ap(2, 2, unc_thread=UncThread(diameter_fraction="1/4", tpi=20, series=UncSeries.UNF))
+    a = _ap(
+        1,
+        1,
+        unc_thread=UncThread(diameter_fraction="1/4", tpi=20, series=UncSeries.UNC),
+    )
+    b = _ap(
+        2,
+        2,
+        unc_thread=UncThread(diameter_fraction="1/4", tpi=20, series=UncSeries.UNF),
+    )
     assert not attachment_points_match(a, b)
 
 
 def test_iso_and_unc_never_match_each_other():
     a = _ap(1, 1, iso_thread=IsoThread(diameter_mm=8, pitch_mm=1.25))
-    b = _ap(2, 2, unc_thread=UncThread(diameter_fraction="1/4", tpi=20, series=UncSeries.UNC))
+    b = _ap(
+        2,
+        2,
+        unc_thread=UncThread(diameter_fraction="1/4", tpi=20, series=UncSeries.UNC),
+    )
     assert not attachment_points_match(a, b)
 
 
@@ -94,9 +114,15 @@ def test_two_bare_attachment_points_never_match():
 
 
 def test_parts_could_fit_requires_different_types_and_identity():
-    a = AugmentedPart(id=1, part_type_id=1, description="a", colour_id=1, manufacturer_id=1)
-    b = AugmentedPart(id=2, part_type_id=1, description="b", colour_id=1, manufacturer_id=1)
-    c = AugmentedPart(id=3, part_type_id=2, description="c", colour_id=1, manufacturer_id=1)
+    a = AugmentedPart(
+        id=1, part_type_id=1, description="a", colour_id=1, manufacturer_id=1
+    )
+    b = AugmentedPart(
+        id=2, part_type_id=1, description="b", colour_id=1, manufacturer_id=1
+    )
+    c = AugmentedPart(
+        id=3, part_type_id=2, description="c", colour_id=1, manufacturer_id=1
+    )
     assert not parts_could_fit(a, b)
     assert parts_could_fit(a, c)
     assert not parts_could_fit(a, a)

tests/test_ldap_login.py

@@ -80,9 +80,7 @@ async def test_ldap_login_is_idempotent(
         assert await user_crud.count(db) == 1
 
 
-async def test_ldap_login_bad_credentials(
-    client, seeded, monkeypatch, ldap_enabled
-):
+async def test_ldap_login_bad_credentials(client, seeded, monkeypatch, ldap_enabled):
     async def fake_authenticate(username, password):
         return None
 

tests/test_scope_guide.py

@@ -1,7 +1,10 @@
 import pytest
 
+from app.models.attachment_point import AttachmentPoint
+from app.models.attachment_point_name import AttachmentPointName
 from app.models.augmented_part import AugmentedPart
 from app.models.fit import Fit, FitLabel
+from app.models.iso_thread import IsoThread
 from app.models.part_type import PartType
 from app.models.scope_info import ScopeInfo
 from app.models.sub_part_type import SubPartType
@@ -31,7 +34,9 @@ async def _seed_guide_data(db):
         db.add(p)
         return p
 
-    s1 = part("Alpha 3-18x50", scope_t.id, manufacturer_id=10, sub_part_type_id=rifle.id)
+    s1 = part(
+        "Alpha 3-18x50", scope_t.id, manufacturer_id=10, sub_part_type_id=rifle.id
+    )
     s2 = part("Zeta 1-6x24", scope_t.id, manufacturer_id=20, sub_part_type_id=reddot.id)
     fc1 = part("Flip cover 50mm", cover_t.id)
     a1 = part("ARD 50mm", ard_t.id)
@@ -43,6 +48,7 @@ async def _seed_guide_data(db):
             augmented_part_id=s1.id,
             magnification_min=3,
             magnification_max=18,
+            objective_lens_diameter_mm=50,
             objective_thread_pitch="M52x0.75",
         )
     )
@@ -169,9 +175,7 @@ async def test_build_filters_by_required_fit_type(db_sessionmaker):
 
 
 async def _web_login(client, email, password="secret123"):
-    resp = await client.post(
-        "/login", data={"email": email, "password": password}
-    )
+    resp = await client.post("/login", data={"email": email, "password": password})
     assert resp.status_code == 303
 
 
@@ -199,7 +203,93 @@ async def test_scopes_page_renders_rows_and_fits(
     assert "Flip cover 50mm" in body  # a matching part in a fit column
     assert "fit-badge-exact" in body  # the exact fit badge
     assert "M52x0.75" in body  # scope info: objective thread
-    assert "3–18×" in body  # magnification range, integral values un-padded
+    assert "3-18" in body  # magnification range, integral values un-padded
+
+
+@pytest.mark.asyncio
+async def test_build_includes_objective_lens_diameter(db_sessionmaker):
+    async with db_sessionmaker() as db:
+        await _seed_guide_data(db)
+        guide = await scope_guide.build(db)
+
+    rows = {r["scope"].description: r for r in guide["rows"]}
+    assert rows["Alpha 3-18x50"]["info"].objective_lens_diameter_mm == 50
+    assert rows["Zeta 1-6x24"]["info"] is None
+
+
+@pytest.mark.asyncio
+async def test_build_prefers_objective_attachment_point_over_scope_info(
+    db_sessionmaker,
+):
+    async with db_sessionmaker() as db:
+        ids = await _seed_guide_data(db)
+        apn = AttachmentPointName(name="Objective")
+        db.add(apn)
+        await db.flush()
+        iso = IsoThread(diameter_mm=44, pitch_mm=0.5)
+        db.add(iso)
+        await db.flush()
+        db.add(
+            AttachmentPoint(
+                augmented_part_id=ids["s1"].id,
+                attachment_point_name_id=apn.id,
+                iso_thread_id=iso.id,
+            )
+        )
+        await db.commit()
+
+        guide = await scope_guide.build(db)
+
+    rows = {r["scope"].description: r for r in guide["rows"]}
+    s1_ap = rows["Alpha 3-18x50"]["objective_attachment_point"]
+    assert s1_ap is not None
+    assert s1_ap.iso_thread.diameter_mm == 44
+    # No "Objective"-named attachment point for s2 -> falls back to None.
+    assert rows["Zeta 1-6x24"]["objective_attachment_point"] is None
+
+
+@pytest.mark.asyncio
+async def test_scopes_page_renders_objective_attachment_point_thread(
+    client, seeded, make_user, db_sessionmaker
+):
+    async with db_sessionmaker() as db:
+        ids = await _seed_guide_data(db)
+        apn = AttachmentPointName(name="Objective")
+        db.add(apn)
+        await db.flush()
+        iso = IsoThread(diameter_mm=44, pitch_mm=0.5)
+        db.add(iso)
+        await db.flush()
+        db.add(
+            AttachmentPoint(
+                augmented_part_id=ids["s1"].id,
+                attachment_point_name_id=apn.id,
+                iso_thread_id=iso.id,
+            )
+        )
+        await db.commit()
+
+    await make_user("reader5@example.com", role_ids=[seeded["roles"]["user"].id])
+    await _web_login(client, "reader5@example.com")
+    resp = await client.get("/scopes")
+    assert resp.status_code == 200
+    body = resp.text
+    # The attachment point's thread spec wins over ScopeInfo.objective_thread_pitch.
+    assert "M44.0×0.5" in body
+    assert "M52x0.75" not in body
+
+
+@pytest.mark.asyncio
+async def test_scopes_page_renders_objective_lens_diameter_in_magnification(
+    client, seeded, make_user, db_sessionmaker
+):
+    async with db_sessionmaker() as db:
+        await _seed_guide_data(db)
+    await make_user("reader4@example.com", role_ids=[seeded["roles"]["user"].id])
+    await _web_login(client, "reader4@example.com")
+    resp = await client.get("/scopes")
+    assert resp.status_code == 200
+    assert "3-18x50" in resp.text
 
 
 @pytest.mark.asyncio

tests/test_scope_import.py

@@ -19,7 +19,7 @@ HEADERS = [
     "model",
     "magnification_min",
     "magnification_max",
-    "objective_lens_outside_diameter_mm",
+    "objective_lens_diameter_mm",
     "model_suffix",
     "sub_part_type",
     "product_number",
@@ -52,7 +52,7 @@ def _scope_row(**overrides):
         "model": "Viper",
         "magnification_min": 5,
         "magnification_max": 25,
-        "objective_lens_outside_diameter_mm": 56,
+        "objective_lens_diameter_mm": 56,
         "model_suffix": "PST",
         "sub_part_type": "Riflescope",
         "product_number": "SCOPE-A",
@@ -141,6 +141,7 @@ async def test_import_creates_scope_with_info_and_attachment_points(db_sessionma
         assert info.magnification_min == 5
         assert info.magnification_max == 25
         assert info.model_suffix == "PST"
+        assert info.objective_lens_diameter_mm == 56
         assert info.objective_thread_pitch == "0.75"
 
         aps = await attachment_point_crud.list_for_augmented_part(db, part.id)
@@ -151,14 +152,13 @@ async def test_import_creates_scope_with_info_and_attachment_points(db_sessionma
         assert len(by_label["Ocular"]) == 1
         assert by_label["Ocular"][0].static_connection.od_mm == 40
 
+        # The lens diameter is descriptive only: the sole Objective point is the
+        # thread.
         objectives = by_label["Objective"]
-        assert len(objectives) == 2  # static OD + thread
-        static_obj = [a for a in objectives if a.static_connection is not None]
-        thread_obj = [a for a in objectives if a.iso_thread is not None]
-        assert static_obj and static_obj[0].static_connection.od_mm == 56
-        assert thread_obj
-        assert thread_obj[0].iso_thread.diameter_mm == 40
-        assert thread_obj[0].iso_thread.pitch_mm == 0.75
+        assert len(objectives) == 1
+        assert objectives[0].static_connection is None
+        assert objectives[0].iso_thread.diameter_mm == 40
+        assert objectives[0].iso_thread.pitch_mm == 0.75
 
 
 async def test_import_resolves_ocular_and_objective_fits(db_sessionmaker):
@@ -200,7 +200,7 @@ async def test_import_upserts_on_product_number(db_sessionmaker):
 
         # Attachment points were rebuilt, not duplicated.
         aps = await attachment_point_crud.list_for_augmented_part(db, matching[0].id)
-        assert len(aps) == 3
+        assert len(aps) == 2
 
 
 async def test_row_without_product_number_is_skipped(db_sessionmaker):