style: run black and ruff over the committed sources

Pure formatting — import ordering and black's line wrapping. No behaviour
change. Kept out of the feature commits so their diffs stay readable.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018jy52j9GRZ6XKa1Zt21LLj

accounts.py

@@ -44,9 +44,7 @@ async def list_directory_users(
                 username=account.username,
                 email=account.email,
                 wallets=[
-                    DirectoryWallet(
-                        id=w.id, name=w.name, balance_msat=w.balance_msat
-                    )
+                    DirectoryWallet(id=w.id, name=w.name, balance_msat=w.balance_msat)
                     for w in wallets
                 ],
             )