feat(share): refactor page and enhance thumbnail extraction

- Extract 8 reusable components from monolithic share page
- Add LLM health indicator with 30s polling
- Implement stealth thumbnail extraction with 4-method cascade
- Integrate real-time thumbnail preview component
- Reduce share page from 306 to ~140 lines
- Add comprehensive outcome documentation

Components:
- UrlInputSection: URL input and extraction trigger
- ProgressIndicator: Loading state display
- ExtractedTextViewer: Collapsible text preview
- RecipeCard: Recipe display with Tandoor integration
- ErrorState: Error handling UI
- LogViewer: System logs with color coding
- LlmHealthIndicator: LLM status with polling
- ThumbnailPreview: Real-time thumbnail display

Thumbnail Methods:
1. Meta tag extraction (og:image, twitter:image)
2. Video poster attribute
3. Instagram embedded JSON data
4. Screenshot fallback

Stories Completed:
- Story 1: Component extraction and refactoring
- Story 2: LLM health status indicator
- Story 3: Enhanced stealth thumbnail extraction
- Story 4: Thumbnail preview integration

Closes: RefactorSharePageAndEnhanceThumbnails

src/routes/share/components/LlmHealthIndicator.svelte

@@ -0,0 +1,58 @@
+<script lang="ts">
+	interface HealthState {
+		status: 'checking' | 'healthy' | 'unhealthy' | 'error';
+		message: string;
+		lastChecked: Date | null;
+	}
+
+	let { pollInterval = 30000 } = $props<{
+		pollInterval?: number;
+	}>();
+
+	let health = $state<HealthState>({
+		status: 'checking',
+		message: '',
+		lastChecked: null
+	});
+
+	async function checkHealth() {
+		try {
+			const res = await fetch('/api/llm-health');
+			const data = await res.json();
+			health = {
+				status: data.status === 'healthy' ? 'healthy' : 'unhealthy',
+				message: data.message,
+				lastChecked: new Date()
+			};
+		} catch (e) {
+			health = {
+				status: 'error',
+				message: e instanceof Error ? e.message : 'Network error',
+				lastChecked: new Date()
+			};
+		}
+	}
+
+	$effect(() => {
+		checkHealth(); // Initial check
+		const interval = setInterval(checkHealth, pollInterval);
+		return () => clearInterval(interval);
+	});
+</script>
+
+<div class="flex items-center gap-2 text-sm">
+	<div class="flex items-center gap-1">
+		{#if health.status === 'checking'}
+			🟡 <span>Checking LLM...</span>
+		{:else if health.status === 'healthy'}
+			🟢 <span class="text-green-600">LLM Ready</span>
+		{:else if health.status === 'unhealthy'}
+			🔴 <span class="text-red-600">LLM Unavailable</span>
+		{:else}
+			🔴 <span class="text-red-600">LLM Error</span>
+		{/if}
+	</div>
+	<div class="text-xs text-gray-500" title={health.message}>
+		{health.lastChecked ? `Last: ${health.lastChecked.toLocaleTimeString()}` : ''}
+	</div>
+</div>