Fix modal rendering + logout SVG icon

- Modal: use inline styles instead of Tailwind classes for position:fixed
  overlay (Tailwind v4 classes weren't applying correctly inside flex)
- Move password modal outside the flex container to top level
- Replace logout text button with SVG logout icon (16x16, Lucide style)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/lib/components/Modal.svelte

@@ -1,5 +1,4 @@
 <script lang="ts">
-	import { t } from '$lib/i18n';
 	let { open = false, title = '', onclose, children } = $props<{
 		open: boolean;
 		title?: string;
@@ -11,12 +10,20 @@
 {#if open}
 	<!-- svelte-ignore a11y_click_events_have_key_events -->
 	<!-- svelte-ignore a11y_no_static_element_interactions -->
-	<div class="fixed inset-0 z-50 flex items-center justify-center bg-black/40" onclick={onclose}>
-		<div class="bg-[var(--color-card)] border border-[var(--color-border)] rounded-lg shadow-lg w-full max-w-md mx-4 p-5"
-			onclick={(e) => e.stopPropagation()}>
-			<div class="flex items-center justify-between mb-4">
-				<h3 class="text-lg font-semibold">{title}</h3>
-				<button onclick={onclose} class="text-[var(--color-muted-foreground)] hover:text-[var(--color-foreground)] text-lg leading-none">&times;</button>
+	<div
+		style="position: fixed; top: 0; left: 0; right: 0; bottom: 0; z-index: 9999; display: flex; align-items: center; justify-content: center; background: rgba(0,0,0,0.5);"
+		onclick={onclose}
+	>
+		<div
+			style="background: var(--color-card); border: 1px solid var(--color-border); border-radius: 0.5rem; box-shadow: 0 10px 25px rgba(0,0,0,0.3); width: 100%; max-width: 28rem; margin: 1rem; padding: 1.25rem;"
+			onclick={(e) => e.stopPropagation()}
+		>
+			<div style="display: flex; align-items: center; justify-content: space-between; margin-bottom: 1rem;">
+				<h3 style="font-size: 1.125rem; font-weight: 600;">{title}</h3>
+				<button onclick={onclose}
+					style="color: var(--color-muted-foreground); font-size: 1.25rem; line-height: 1; cursor: pointer; background: none; border: none; padding: 0.25rem;">
+					&times;
+				</button>
 			</div>
 			{@render children()}
 		</div>