feat: Sprint A Wahab review batch — categories, property hierarchy, priority grouping

Items 1-5, 9, 11 from denya-wahab-feedback-s2:
- Category.show_in_form (alert-only flag): Gas Leak hidden from issue picker
  but kept urgent for SLA/alert and reporting; emergency quick path on the
  new-issue form creates urgent tickets via include_hidden categories.
- Seed: Aluminum/Glass, Carpentry, Mould & Damp (Medium default) maintenance
  categories; Lost Property renamed Missing Item (+ sub).
- One alembic migration: add show_in_form (backfill True, Gas Leak False) +
  data rename Lost Property -> Missing Item.
- Property -> Building -> Apartment cascade with searchable apartment combobox
  on the new-issue form and ticket list filters; /api/tickets/units gains
  building filter + /units/grouped variant; /api/tickets gains additive
  building/unit_id filters. apartment_mapping.json committed (deterministic).
- Group-by-priority toggle on /tickets (four sections + unknown bucket,
  age-sortable, composes with filters, URL deep links), FM dashboard active
  tickets, and CS dashboard priority card click-through.
- Tests: 13 new (category visibility, seed idempotency/sync, unit grouping,
  ticket building/unit filters).

alembic/versions/b2f4a6c8e0d2_category_show_in_form_and_missing_item_rename.py

@@ -0,0 +1,60 @@
+"""category show_in_form column + Lost Property → Missing Item rename
+
+Revision ID: b2f4a6c8e0d2
+Revises: 795c6b95f637
+Create Date: 2026-08-02 00:00:00.000000
+
+Sprint A (Wahab feedback batch): one schema change + one data rename.
+
+* Add ``categories.show_in_form`` (bool, default True) and backfill existing
+  rows to True; flip Gas Leak to False (alert-only: still urgent for SLA/alert
+  and reporting, but hidden from the new-issue category picker).
+* Rename the Customer Service category ``Lost Property`` → ``Missing Item``.
+  The seed is insert-if-missing, so without this data migration an existing
+  database would keep the old row and the seed would create a duplicate.
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = 'b2f4a6c8e0d2'
+down_revision: Union[str, Sequence[str], None] = '795c6b95f637'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Add show_in_form, backfill True, hide Gas Leak, rename Lost Property."""
+    op.add_column(
+        'categories',
+        sa.Column(
+            'show_in_form',
+            sa.Boolean(),
+            nullable=False,
+            server_default=sa.true(),
+            comment='Visible in the new-issue category picker (False = alert-only, e.g. Gas Leak)',
+        ),
+    )
+    # Backfill: Gas Leak stays in the SLA/alert table (urgent) but is hidden
+    # from the new-issue picker.
+    op.execute(
+        "UPDATE categories SET show_in_form = 0 "
+        "WHERE type = 'emergency' AND name = 'Gas Leak' AND parent_id IS NULL"
+    )
+    # Rename Lost Property → Missing Item (data migration; seed is insert-if-missing).
+    op.execute(
+        "UPDATE categories SET name = 'Missing Item' "
+        "WHERE type = 'cs' AND name = 'Lost Property'"
+    )
+
+
+def downgrade() -> None:
+    """Reverse the rename and drop the column."""
+    op.execute(
+        "UPDATE categories SET name = 'Lost Property' "
+        "WHERE type = 'cs' AND name = 'Missing Item'"
+    )
+    op.drop_column('categories', 'show_in_form')