fix: delete stale FR→EN glossaries + convert all remaining to multilingual

Old glossaries imported before enrichment have target_language='en' and no
translations dict — they're stale duplicates. This migration:

1. Deletes old FR→EN glossaries with empty/null translations (no Persian, etc.)
2. Renames multilingual glossaries from 'Anglais' to 'Multilingue'
3. Sets ALL remaining FR glossaries to target_language='multi'
4. Users re-import from enriched templates to get Persian/Arabic/etc. terms

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

alembic/versions/c8d9e0f1a2b3_rename_multilingual_glossaries.py

@@ -1,12 +1,12 @@
-"""Rename multilingual glossaries from 'Anglais' to 'Multilingue'
+"""Clean up glossaries: delete old FR→EN imports, rename multilingual ones
 
 Revision ID: c8d9e0f1a2b3
 Revises: b7c8d9e0f1a2
 Create Date: 2026-05-31
 
-Previous migration b7c8d9e0f1a2 set target_language='multi' but the rename
+Old glossaries imported before multilingual enrichment have target_language='en'
-part was added after the migration was already applied on the server.
+and no translations. They are stale duplicates of the enriched templates.
-This migration handles the rename separately.
+This migration deletes them so users re-import the enriched versions.
 """
 
 from typing import Sequence, Union
@@ -22,7 +22,59 @@ depends_on: Union[str, Sequence[str], None] = None
 
 
 def upgrade() -> None:
-    # Rename glossaries that are multilingual but still have "Anglais" in name
+    # 1. Delete old FR→EN glossaries that don't have multilingual translations
+    #    (imported before enrichment, they are stale duplicates)
+    op.execute("""
+        DELETE FROM glossary_terms
+        WHERE glossary_id IN (
+            SELECT g.id
+            FROM glossaries g
+            WHERE g.target_language = 'en'
+              AND g.source_language = 'fr'
+              AND g.id IN (
+                SELECT g2.id
+                FROM glossaries g2
+                JOIN glossary_terms gt ON gt.glossary_id = g2.id
+                WHERE gt.translations IS NULL
+                   OR jsonb_typeof(gt.translations) = 'null'
+                   OR (SELECT count(*) FROM jsonb_object_keys(COALESCE(gt.translations, '{}'))) = 0
+                LIMIT 1
+              )
+        )
+    """)
+
+    op.execute("""
+        DELETE FROM glossaries
+        WHERE target_language = 'en'
+          AND source_language = 'fr'
+          AND id IN (
+            SELECT g.id
+            FROM glossaries g
+            LEFT JOIN glossary_terms gt ON gt.glossary_id = g.id
+            WHERE gt.translations IS NULL
+               OR jsonb_typeof(COALESCE(gt.translations, 'null')) IN ('null', 'null')
+            LIMIT 1
+          )
+    """)
+
+    # 2. Rename remaining multilingual glossaries from 'Anglais' to 'Multilingue'
+    op.execute("""
+        UPDATE glossaries
+        SET name = REPLACE(name, 'Anglais', 'Multilingue')
+        WHERE target_language = 'multi'
+          AND name LIKE '%%Anglais%%'
+    """)
+
+    # 3. Also set any remaining FR glossaries with target_language='en' to 'multi'
+    #    (they might have been imported from enriched templates but migration missed them)
+    op.execute("""
+        UPDATE glossaries
+        SET target_language = 'multi'
+        WHERE source_language = 'fr'
+          AND target_language = 'en'
+    """)
+
+    # 4. Rename those too
     op.execute("""
         UPDATE glossaries
         SET name = REPLACE(name, 'Anglais', 'Multilingue')
@@ -32,9 +84,14 @@ def upgrade() -> None:
 
 
 def downgrade() -> None:
+    # Cannot restore deleted glossaries, just revert names and target_language
     op.execute("""
         UPDATE glossaries
         SET name = REPLACE(name, 'Multilingue', 'Anglais')
-        WHERE target_language = 'multi'
+        WHERE name LIKE '%%Multilingue%%'
-          AND name LIKE '%%Multilingue%%'
+    """)
+    op.execute("""
+        UPDATE glossaries
+        SET target_language = 'en'
+        WHERE target_language = 'multi'
     """)