db: the doubled CHECK list was six, not four (#3275)

Run 5029 confirmed the four renames landed and surfaced two I had missed:
external_link's host and status CHECKs are doubled the same way. They did
not show in run 5026's diff because BOTH sides produced the doubled form
back then — external_link.py pre-prefixed its names, so the models
matched the chain's mistake. Switching all six models to bare names is
what exposed the two the migration did not cover.

The list in the file now comes from matching ck_(\w+?)_ck_\1_ against the
chain's own pg_dump, rather than from reading migrations by eye. Reading
by eye is what missed these, in the same way it earlier missed a UNIQUE
constraint sitting two lines above the index being looked at.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017QHszn9H8VBvx5Ke8x1hvw

alembic/versions/0088_reconcile_models_with_schema.py

@@ -29,13 +29,15 @@ guarantee built from different objects, which is why the two schemas did not
 line up. The model now declares the constraint and the plain index separately,
 so it describes what is actually there. No DDL is needed for it.
 
-Also here: four CHECK constraints whose names carry their table prefix TWICE.
+Also here: six CHECK constraints whose names carry their table prefix TWICE.
 
 `base.py`'s naming convention is `ck_%(table_name)s_%(constraint_name)s`, and
 unlike the uq/fk/ix entries it applies even to a constraint that already has a
-name. Four migrations passed an already-prefixed name, so the convention
+name. Six migrations passed an already-prefixed name, so the convention
 prefixed it again:
 
+    ck_external_link_ck_external_link_host
+    ck_external_link_ck_external_link_status
     ck_import_settings_ck_import_settings_singleton
     ck_ml_settings_ck_ml_settings_singleton
     ck_post_ck_post_translation_override
@@ -67,7 +69,17 @@ branch_labels: Union[str, Sequence[str], None] = None
 depends_on: Union[str, Sequence[str], None] = None
 
 # (table, doubled name, single-prefix name)
+#
+# Six, not the four a first read of the migrations turned up. The list that
+# settles it is the one extracted from the chain's pg_dump by matching
+# `ck_(\w+?)_ck_\1_` — reading the migrations by eye missed external_link
+# twice over, in the same way an earlier pass missed a UNIQUE constraint two
+# lines above the index it was looking at (see the sha256 note above).
 DOUBLED_CHECKS = (
+    ("external_link", "ck_external_link_ck_external_link_host",
+     "ck_external_link_host"),
+    ("external_link", "ck_external_link_ck_external_link_status",
+     "ck_external_link_status"),
     ("import_settings", "ck_import_settings_ck_import_settings_singleton",
      "ck_import_settings_singleton"),
     ("ml_settings", "ck_ml_settings_ck_ml_settings_singleton",