drop old db tables and remove old functions

migrations.py

@@ -628,3 +628,24 @@ async def m015_convert_to_single_amount_field(db):
         CREATE INDEX idx_entry_lines_account ON entry_lines (account_id)
         """
     )
+
+
+async def m016_drop_obsolete_journal_tables(db):
+    """
+    Drop journal_entries and entry_lines tables.
+
+    Castle now uses Fava/Beancount as the single source of truth for accounting data.
+    These tables are no longer written to or read from.
+
+    All journal entry operations now:
+    - Write: Submit to Fava via FavaClient.add_entry()
+    - Read: Query Fava via FavaClient.get_entries()
+
+    Migration completed as part of Castle extension cleanup (Nov 2025).
+    No backwards compatibility concerns - user explicitly approved.
+    """
+    # Drop entry_lines first (has foreign key to journal_entries)
+    await db.execute("DROP TABLE IF EXISTS entry_lines")
+
+    # Drop journal_entries
+    await db.execute("DROP TABLE IF EXISTS journal_entries")