feat: add optional ticket selection to planning report generation

Add a `numbers` form field to the planning report endpoint, allowing
admins to generate a report for a specific subset of open tickets
instead of always planning all open tickets. The selected numbers are
parsed from a comma-separated string, deduplicated, and passed to the
background job. The job's scope is recorded in the audit log and the
Devii tool description is updated to document the new parameter.

tests/e2e/admin/issues/planning.py

@@ -0,0 +1,22 @@
+# retoor <retoor@molodetz.nl>
+
+from tests.conftest import BASE_URL
+
+
+def test_planning_page_renders_for_admin(alice):
+    page, _ = alice
+    page.goto(
+        f"{BASE_URL}/admin/issues/planning", wait_until="domcontentloaded"
+    )
+    assert page.url.endswith("/admin/issues/planning")
+    page.locator("h1:has-text('Ticket Planning')").wait_for(state="visible")
+    assert page.is_visible("text=phased implementation document")
+
+
+def test_planning_page_blocks_members(bob):
+    page, _ = bob
+    page.goto(
+        f"{BASE_URL}/admin/issues/planning", wait_until="domcontentloaded"
+    )
+    assert "/admin/issues/planning" not in page.url
+    assert not page.is_visible("h1:has-text('Ticket Planning')")