Refactor create_event_modal into modular components

- Split massive 27K line modal into focused components
- Created event_form module with 6 tab components:
  * BasicDetailsTab - main event info with recurrence options properly positioned
  * AdvancedTab - status, privacy, priority
  * PeopleTab - organizer and attendees
  * CategoriesTab - event categories
  * LocationTab - location information
  * RemindersTab - reminder settings
- Added shared types and data structures
- Created new CreateEventModalV2 using modular architecture
- Recurrence options now positioned directly after repeat/reminder pickers

🤖 Generated with [Claude Code](https://claude.ai/code)

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

frontend/src/components/event_form/reminders.rs

@@ -0,0 +1,52 @@
+use super::types::*;
+use wasm_bindgen::JsCast;
+use web_sys::HtmlSelectElement;
+use yew::prelude::*;
+
+#[function_component(RemindersTab)]
+pub fn reminders_tab(props: &TabProps) -> Html {
+    let data = &props.data;
+    
+    let on_reminder_change = {
+        let data = data.clone();
+        Callback::from(move |e: Event| {
+            if let Some(target) = e.target() {
+                if let Ok(select) = target.dyn_into::<HtmlSelectElement>() {
+                    let mut event_data = (*data).clone();
+                    event_data.reminder = match select.value().as_str() {
+                        "15min" => ReminderType::Minutes15,
+                        "30min" => ReminderType::Minutes30,
+                        "1hour" => ReminderType::Hour1,
+                        "1day" => ReminderType::Day1,
+                        "2days" => ReminderType::Days2,
+                        "1week" => ReminderType::Week1,
+                        _ => ReminderType::None,
+                    };
+                    data.set(event_data);
+                }
+            }
+        })
+    };
+
+    html! {
+        <div class="tab-panel">
+            <div class="form-group">
+                <label for="event-reminder">{"Default Reminder"}</label>
+                <select
+                    id="event-reminder"
+                    class="form-input"
+                    onchange={on_reminder_change}
+                >
+                    <option value="none" selected={matches!(data.reminder, ReminderType::None)}>{"None"}</option>
+                    <option value="15min" selected={matches!(data.reminder, ReminderType::Minutes15)}>{"15 minutes before"}</option>
+                    <option value="30min" selected={matches!(data.reminder, ReminderType::Minutes30)}>{"30 minutes before"}</option>
+                    <option value="1hour" selected={matches!(data.reminder, ReminderType::Hour1)}>{"1 hour before"}</option>
+                    <option value="1day" selected={matches!(data.reminder, ReminderType::Day1)}>{"1 day before"}</option>
+                    <option value="2days" selected={matches!(data.reminder, ReminderType::Days2)}>{"2 days before"}</option>
+                    <option value="1week" selected={matches!(data.reminder, ReminderType::Week1)}>{"1 week before"}</option>
+                </select>
+                <p class="form-help-text">{"Set when you want to be reminded about this event."}</p>
+            </div>
+        </div>
+    }
+}