feat(web): CFItemType の逆参照「この種別の項目」を追加

docs/spec/web-ui.md

@@ -167,6 +167,7 @@ Beyond the always-present fields, these **conditional / relational sections** ap
 | **Referenced by (other institutions)** / 参照元（他機関） | CFItem | ✓ | ✓ | other-tenant associations whose destination is this item. **Public origins only** (private adopters never surfaced); current tenant excluded; excludes `isChildOf` |
 | **Referring criteria** | CFItem | ✓ | ✓ | a CFRubricCriterion links to this item via `CFItemURI` |
 | **Items setting this subject** / この分野を設定している項目 | CFSubject | ✓ **tenant-wide** (all docs) | ✓ **current document only** (案B) | items whose `subjectURI` references the subject. Top-20 + count + "Show more". Scope = `doc` presence (page None → tenant-wide; pane → that doc). `subject` string-only refs not matched |
+| **Items of this type** / この種別の項目 | CFItemType | ✓ **tenant-wide** | ✓ **current document only** (案B) | items whose `cf_item_type_id` FK is this type. Same shape/scope as the subject row; matched by FK (no JSONB). Fragment route `/item-type/{id}/items` |
 | **Definitions** (Item Types / Concepts / Subjects / Licenses / Groupings) | CFDocument (tree) | — | ✓ | the lookups this document references (CFPackage `CFDefinitions` scope); each is a navigable tree node |
 | **Effective license** | CFItem / CFDocument | ✓ | ✓ | item's own license, else inherited from document (labeled "from document") |
 
@@ -244,7 +245,9 @@ When `/uri/{uuid}` resolves to a lookup, show common + specific fields:
 - **Standalone `/uri/{subject}` page** — **tenant-wide**: every item in the tenant setting this subject, across all documents. (A subject is a tenant-owned lookup with no owning document, so the page has no document context — `doc` is None.)
 - **Tree right pane** (subject selected via the current document's Definitions) — **restricted to the current document**: only that document's items. This keeps the pane consistent with its document-scoped tree (every listed item is a node in the same tree, so links never jump to another document), keeps the list small, and keeps the query cheap. The `doc` query param threads this scope through "Show more"; `subject_items.scope_doc` carries the document identifier (None = tenant-wide). The discriminator is simply whether `_detail_extras` receives a `doc` (pane) or not (page).
 
-Other scope notes: **within-tenant only** (no cross-tenant/private gating); items referencing the subject only via the plain `subject` string (no `subjectURI`) are **not** matched; the reusable `fragments/subject_items.html` partial backs both the inline SSR and the fragment route (and is intended for reuse by a future search results list). Other lookups (CFItemType/Concept/License) do not yet have an equivalent reverse list.
+Other scope notes: **within-tenant only** (no cross-tenant/private gating); items referencing the subject only via the plain `subject` string (no `subjectURI`) are **not** matched; the reusable `fragments/subject_items.html` partial backs both the inline SSR and the fragment route (and is intended for reuse by a future search results list).
+
+**CFItemType — "Items of this type" (reverse lookup):** the CFItemType analogue, with the **same** behaviour, surface-based scope (案B), pagination, and `subject_items.html` partial. The only differences: matched by the **`cf_item.cf_item_type_id` FK** (not JSONB; `cf_item_repository.list_items_by_item_type` / `count_items_by_item_type`, keyed by the type's internal PK) — backed by the btree index **`ix_cf_items_tenant_item_type (tenant_id, cf_item_type_id)`** (Postgres does not auto-index FK columns, so the tenant-wide query would otherwise seq-scan), the section label is "Items of this type" / 「この種別の項目」, and the "Show more" fragment route is `GET /{tenant}/item-type/{item-type-id}/items?offset=&limit=[&doc=]`. The shared partial takes an `items_endpoint` so the same markup serves both subject and item-type. CFConcept / CFLicense / CFAssociationGrouping do not yet have an equivalent reverse list (Concept/License would follow the same FK pattern; Grouping lists associations, not items).
 
 ### CFRubric
 

migrations/versions/e2b3c4d5f6a7_index_cf_items_tenant_item_type.py

@@ -0,0 +1,36 @@
+"""add btree index on cf_items (tenant_id, cf_item_type_id)
+
+Speeds up the CFItemType reverse lookup ("items of this type"):
+``WHERE tenant_id = ? AND cf_item_type_id = ?``. PostgreSQL does not create an
+index on FK columns automatically, so without this the tenant-wide list / count
+would seq-scan. The (tenant_id, cf_item_type_id) prefix also serves the count;
+the document-scoped pane query adds cf_document_id (covered by the existing
+ix_cf_items_tenant_document_coding).
+
+Revision ID: e2b3c4d5f6a7
+Revises: d1a2b3c4e5f6
+Create Date: 2026-06-20 00:00:00.000000
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = "e2b3c4d5f6a7"
+down_revision: Union[str, None] = "d1a2b3c4e5f6"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_index(
+        "ix_cf_items_tenant_item_type",
+        "cf_items",
+        ["tenant_id", "cf_item_type_id"],
+        unique=False,
+    )
+
+
+def downgrade() -> None:
+    op.drop_index("ix_cf_items_tenant_item_type", table_name="cf_items")

src/locales/en.json

@@ -66,6 +66,7 @@
     "related_other_institution_in": "Other institution ↩",
     "incoming_refs_label": "Referenced by (other institutions)",
     "subject_items_label": "Items setting this subject",
+    "item_type_items_label": "Items of this type",
     "subject_items_count": "{count} total",
     "show_more": "Show more",
     "related_external": "External",

src/locales/ja.json

@@ -66,6 +66,7 @@
     "related_other_institution_in": "他機関 ↩",
     "incoming_refs_label": "参照元（他機関）",
     "subject_items_label": "この分野を設定している項目",
+    "item_type_items_label": "この種別の項目",
     "subject_items_count": "全 {count} 件",
     "show_more": "もっと見る",
     "related_external": "外部",

src/models/cf_item.py

@@ -21,6 +21,10 @@ class CFItem(Base):
             postgresql_using="gin",
             postgresql_ops={"subject_uri": "jsonb_path_ops"},
         ),
+        # Reverse lookup "items of this type" (CFItemType). Postgres does not
+        # auto-index FK columns, so the tenant-wide `WHERE tenant_id=? AND
+        # cf_item_type_id=?` query would seq-scan without this.
+        Index("ix_cf_items_tenant_item_type", "tenant_id", "cf_item_type_id"),
     )
 
     id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)

src/repositories/cf_item_repository.py

@@ -107,29 +107,13 @@ async def get_cf_item_by_identifier(
     return result.scalar_one_or_none()
 
 
-async def list_items_by_subject(
-    session: AsyncSession,
-    tenant_id: uuid.UUID,
-    subject_identifier: str,
-    *,
-    document_id: uuid.UUID | None = None,
-    offset: int = 0,
-    limit: int = 20,
-) -> list[dict]:
-    """CFItems in this tenant whose ``subject_uri`` references the given subject.
+async def _list_items_where(session: AsyncSession, conditions: list, offset: int, limit: int) -> list[dict]:
+    """Shared body of the reverse-lookup list queries (items using a definition).
 
-    Reverse lookup for the CFSubject detail page ("items setting this subject").
-    Matches via JSONB containment ``subject_uri @> '[{"identifier": <id>}]'``
-    (GIN-indexed). Tenant-scoped. When ``document_id`` is given, additionally
-    restricts to that one document (used by the tree right pane, which is
-    document-scoped; the standalone /uri/ page passes None for the tenant-wide
-    list). Ordered by human_coding_scheme → full_statement → identifier for a
-    stable offset-pagination boundary. Returns
+    Selects the label/link columns, joins the owning document, and applies a
+    stable order for offset pagination. Returns
     ``[{identifier, human_coding_scheme, full_statement, doc_identifier, doc_title}]``.
     """
-    conditions = [CFItem.tenant_id == tenant_id, _subject_uri_contains(subject_identifier)]
-    if document_id is not None:
-        conditions.append(CFItem.cf_document_id == document_id)
     rows = await session.execute(
         select(
             CFItem.identifier,
@@ -160,6 +144,45 @@ async def list_items_by_subject(
     ]
 
 
+async def _count_items_where(session: AsyncSession, conditions: list) -> int:
+    result = await session.execute(select(func.count()).select_from(CFItem).where(*conditions))
+    return int(result.scalar_one())
+
+
+def _subject_conditions(tenant_id: uuid.UUID, subject_identifier: str, document_id: uuid.UUID | None) -> list:
+    conditions = [CFItem.tenant_id == tenant_id, _subject_uri_contains(subject_identifier)]
+    if document_id is not None:
+        conditions.append(CFItem.cf_document_id == document_id)
+    return conditions
+
+
+def _item_type_conditions(tenant_id: uuid.UUID, item_type_id: uuid.UUID, document_id: uuid.UUID | None) -> list:
+    conditions = [CFItem.tenant_id == tenant_id, CFItem.cf_item_type_id == item_type_id]
+    if document_id is not None:
+        conditions.append(CFItem.cf_document_id == document_id)
+    return conditions
+
+
+async def list_items_by_subject(
+    session: AsyncSession,
+    tenant_id: uuid.UUID,
+    subject_identifier: str,
+    *,
+    document_id: uuid.UUID | None = None,
+    offset: int = 0,
+    limit: int = 20,
+) -> list[dict]:
+    """CFItems in this tenant whose ``subject_uri`` references the given subject.
+
+    Reverse lookup for the CFSubject detail page ("items setting this subject").
+    Matches via JSONB containment ``subject_uri @> '[{"identifier": <id>}]'``
+    (GIN-indexed). Tenant-scoped. When ``document_id`` is given, additionally
+    restricts to that one document (the tree right pane is document-scoped; the
+    standalone /uri/ page passes None for the tenant-wide list)."""
+    conditions = _subject_conditions(tenant_id, subject_identifier, document_id)
+    return await _list_items_where(session, conditions, offset, limit)
+
+
 async def count_items_by_subject(
     session: AsyncSession,
     tenant_id: uuid.UUID,
@@ -168,12 +191,35 @@ async def count_items_by_subject(
     document_id: uuid.UUID | None = None,
 ) -> int:
     """Total CFItems referencing the given subject (for the count label).
-    Tenant-scoped; restricted to one document when ``document_id`` is given
-    (same scoping as ``list_items_by_subject``). Call once on the SSR page; the
-    "load more" fragment derives has_more from a limit+1 fetch instead of
-    recounting."""
-    conditions = [CFItem.tenant_id == tenant_id, _subject_uri_contains(subject_identifier)]
-    if document_id is not None:
-        conditions.append(CFItem.cf_document_id == document_id)
-    result = await session.execute(select(func.count()).select_from(CFItem).where(*conditions))
-    return int(result.scalar_one())
+    Same scoping as ``list_items_by_subject``."""
+    return await _count_items_where(session, _subject_conditions(tenant_id, subject_identifier, document_id))
+
+
+async def list_items_by_item_type(
+    session: AsyncSession,
+    tenant_id: uuid.UUID,
+    item_type_id: uuid.UUID,
+    *,
+    document_id: uuid.UUID | None = None,
+    offset: int = 0,
+    limit: int = 20,
+) -> list[dict]:
+    """CFItems of the given CFItemType ("items of this type").
+
+    Reverse lookup for the CFItemType detail page. Matches the FK
+    ``cf_item.cf_item_type_id`` (indexed via the FK) — ``item_type_id`` is the
+    CFItemType's internal PK (``CFItemType.id``), not its CASE identifier.
+    Tenant-scoped; ``document_id`` restricts to one document (pane scope)."""
+    return await _list_items_where(session, _item_type_conditions(tenant_id, item_type_id, document_id), offset, limit)
+
+
+async def count_items_by_item_type(
+    session: AsyncSession,
+    tenant_id: uuid.UUID,
+    item_type_id: uuid.UUID,
+    *,
+    document_id: uuid.UUID | None = None,
+) -> int:
+    """Total CFItems of the given CFItemType (count label). Same scoping as
+    ``list_items_by_item_type``."""
+    return await _count_items_where(session, _item_type_conditions(tenant_id, item_type_id, document_id))