feat(systems): the area vocabulary becomes a global table so a rule can point at one (#3027, milestone 307 step 1)

The eight standard area names already existed — as STANDARD_SYSTEMS, a tuple in
services/systems.py that milestone 297 seeds at inception. A constant cannot be
a foreign key, so nothing outside a project could reference an area: systems.
project_id is NOT NULL, and a rule that spans projects would have to chain
itself to one project's row. And because the list only ever applied on the
inception-seed path, three spellings of one area reached this instance anyway
(CI & runners / CI and Release / CI & release).

- canonical_systems: global, no user_id — a shared project inherits the
  vocabulary instead of re-earning it. Migration 0087 seeds the same eight.
- systems.canonical_id: nullable, SET NULL. Association only — no System is
  renamed and record_systems is untouched, so no record's tags move.
- canonical_slug folds &/and, case and punctuation, so spelling variants map
  mechanically and a real difference ("CI & runners") becomes a proposal a
  human confirms. propose_mappings reports; set_system_canonical is the only
  writer.
- seed_standard_systems now reads the catalog and maps as it mints, so a
  project born standard never needs a reconciliation pass.
- Catalog writes are admin-only; reads are open — a global list anyone can
  extend stops being shared.
- backup: carried by SLUG, not id (ids are per-install). Restore reuses the
  target's own rows and only creates entries an admin added on the source; an
  unknown slug restores unmapped rather than failing.

Rule 22: STANDARD_SYSTEMS is removed, not deprecated. Rule 115: nothing seeded
names an app, repo or house convention. Design in note 3026.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/test_inception.py

@@ -57,9 +57,22 @@ def test_normalize_choices_is_canonical_and_complete():
                                        "design_system_id": None, "seed_systems": False}
 
 
-def test_standard_systems_vocabulary_is_one_list_for_ask_and_seed():
-    from scribe.mcp.tools.systems import _STANDARD_SYSTEMS
-    from scribe.services.systems import STANDARD_SYSTEMS
-    assert _STANDARD_SYSTEMS == tuple(n for n, _ in STANDARD_SYSTEMS)
-    assert len(STANDARD_SYSTEMS) == 8 and all(charter for _, charter in STANDARD_SYSTEMS)
+def test_standard_systems_vocabulary_reads_the_catalog_not_a_constant():
+    """The vocabulary moved from a module constant to the global catalog table
+    (milestone 307): a constant cannot be a foreign key, so nothing outside a
+    project could reference an area. The seed and the bootstrap ask must both
+    read the table, or the list they show and the list they mint diverge."""
+    import inspect
+
+    from scribe.services import systems as systems_svc
+
+    assert not hasattr(systems_svc, "STANDARD_SYSTEMS"), (
+        "the constant is gone — the catalog table is the single source"
+    )
+    source = inspect.getsource(systems_svc.seed_standard_systems)
+    assert "list_canonical_systems" in source
+    assert "canonical_id=entry.id" in source, (
+        "a seeded System must be mapped as it is created, or a project born "
+        "from the standard set still needs a reconciliation pass"
+    )