fix: pin black to 26.3.1 across all environments

- Pin black version in requirements-dev.txt (was >=24.0.0)
- Update pre-commit to use black 26.3.1 with Python 3.12
- Add language_version: python3.12 to pre-commit black hook
- Reformat files with new black version for consistency

app/pages/options.py

@@ -137,8 +137,7 @@ async def options_page() -> None:
                     </thead>
                     <tbody>
             """
-                + "".join(
-                    f"""
+                + "".join(f"""
                         <tr class='border-b border-slate-200 dark:border-slate-800'>
                             <td class='px-4 py-3 font-medium text-slate-900 dark:text-slate-100'>{row['symbol']}</td>
                             <td class='px-4 py-3 text-slate-600 dark:text-slate-300'>{row['type'].upper()}</td>
@@ -149,9 +148,7 @@ async def options_page() -> None:
                             <td class='px-4 py-3 text-slate-600 dark:text-slate-300'>Δ {float(row.get('delta', 0.0)):+.3f} · Γ {float(row.get('gamma', 0.0)):.3f} · Θ {float(row.get('theta', 0.0)):+.3f} · V {float(row.get('vega', 0.0)):.3f}</td>
                             <td class='px-4 py-3 text-sky-600 dark:text-sky-300'>Use quick-add buttons below</td>
                         </tr>
-                """
-                    for row in rows
-                )
+                """ for row in rows)
                 + (
                     ""
                     if rows