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

migrations.py

@@ -16,8 +16,7 @@ schema.
 async def m001_initial(db):
     """Payroll contracts — the standing "pay X this much, this often" rows."""
 
-    await db.execute(
-        f"""
+    await db.execute(f"""
         CREATE TABLE payroll.contracts (
             id TEXT PRIMARY KEY,
             employee_id TEXT NOT NULL,
@@ -37,16 +36,13 @@ async def m001_initial(db):
             created_at TIMESTAMP NOT NULL DEFAULT {db.timestamp_now},
             updated_at TIMESTAMP NOT NULL DEFAULT {db.timestamp_now}
         );
-        """
-    )
+        """)
 
     # The scheduler's hot path is "every contract still eligible to pay".
     # NOTE: the schema qualifier goes on the INDEX name, not the table —
     # SQLite attaches the extension DB as schema `payroll`, and
     # `CREATE INDEX ON schema.table` is a syntax error there.
-    await db.execute(
-        "CREATE INDEX payroll.idx_contracts_status ON contracts (status);"
-    )
+    await db.execute("CREATE INDEX payroll.idx_contracts_status ON contracts (status);")
     # Employee-facing lookups ("show me my payroll lines") filter by account.
     await db.execute(
         "CREATE INDEX payroll.idx_contracts_employee ON contracts (employee_id);"