feat(edit): form redesign, optional fields, OptionCard dialogs, expressive motion

Post-v1.2.0 design iteration on the event form, reviewed slice by slice
on-device:

- Form rebuilt on the detail screen's card system: tonal EditCards with
  gutter icons (centred on the first row, top-aligned for multiline),
  borderless inline fields (placeholders at half opacity), calendar-coloured
  title accent, no dividers, bare top bar
- Optional sections (location, description, reminders, availability,
  visibility) with per-user defaults in Settings ("New event form" toggles);
  hidden ones unfold via a "More fields" picker dialog
- Reminders: stacked rows + full-width borderless add; two-step picker
  (one-tap presets, then custom amount + minutes/hours/days/weeks dropdown);
  written as METHOD_ALERT Reminders rows. Availability busy/free segmented
  toggle; visibility selector with per-level icons
- OptionCard (ui/common) is now the app-wide selection-dialog standard;
  calendar picker, visibility, more-fields, reminder presets and the
  recurring-delete chooser all use it — radio-row dialogs removed
- MaterialExpressiveTheme with MotionScheme.standard() (expressive bounce
  felt overdone); FAB stack + field reveals animate on theme springs;
  jump-to-today slides toward today's actual direction
- IME: adjustResize + imePadding so the keyboard never pans the form
- Tests: form-field prefs round-trips, availability/access provider
  mappings; DE+EN strings throughout

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/src/main/AndroidManifest.xml

@@ -18,7 +18,8 @@
         tools:targetApi="35">
         <activity
             android:name=".MainActivity"
-            android:exported="true">
+            android:exported="true"
+            android:windowSoftInputMode="adjustResize">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />