feat: add Umami analytics with tagged events

Add Umami web analytics tracking script to the layout head, and
instrument all interactive elements with event tracking:

Declarative (data-umami-event attributes):
- Category selector: select_category
- Style selector: select_style
- Intensity slider: adjust_intensity
- Prompt toggle: toggle_prompt (with open/close action)

Programmatic (umami.track with metadata):
- convert_click: { style, intensity }
- convert_success: { style, intensity, model }
- convert_error: { style, intensity, error }
- copy_result: { style }

src/app.d.ts

@@ -8,6 +8,11 @@ declare global {
 		// interface PageState {}
 		// interface Platform {}
 	}
+
+	// Umami analytics tracker (injected by script tag)
+	const umami: {
+		track(event: string, data?: Record<string, string | number | boolean>): void;
+	};
 }
 
 export {};

src/routes/+layout.svelte

@@ -6,6 +6,7 @@
 
 <svelte:head>
 	<link rel="icon" href="data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'><text y='.9em' font-size='90'>✨</text></svg>" />
+	<script defer src="https://wa.santhoshj.com/script.js" data-website-id="1004961a-2b1f-4c45-95a6-78059acac472"></script>
 </svelte:head>
 
 {@render children()}

src/routes/+page.svelte

@@ -78,6 +78,10 @@
 	async function handleConvert() {
 		if (!canConvert) return;
 
+		if (typeof umami !== 'undefined') {
+			umami.track('convert_click', { style: selectedStyleId, intensity });
+		}
+
 		loading = true;
 		error = '';
 		outputText = '';
@@ -108,14 +112,26 @@
 			systemPrompt = result.systemPrompt;
 			userMessage = result.userMessage;
 			modelLabel = result.modelLabel;
+
+			if (typeof umami !== 'undefined') {
+				umami.track('convert_success', { style: selectedStyleId, intensity, model: result.modelLabel });
+			}
 		} catch (err) {
 			error = err instanceof Error ? err.message : 'Something went wrong';
+
+			if (typeof umami !== 'undefined') {
+				umami.track('convert_error', { style: selectedStyleId, intensity, error });
+			}
 		} finally {
 			loading = false;
 		}
 	}
 
 	async function handleCopy() {
+		if (typeof umami !== 'undefined') {
+			umami.track('copy_result', { style: selectedStyleId });
+		}
+
 		try {
 			await navigator.clipboard.writeText(outputText);
 			copied = true;
@@ -157,6 +173,7 @@
 					bind:value={selectedCategoryId}
 					onchange={onCategoryChange}
 					disabled={loading}
+					data-umami-event="select_category"
 				>
 					<option value="">Choose a category...</option>
 					{#each categories as cat}
@@ -167,7 +184,7 @@
 
 			<div class="form-group">
 				<label for="style">Style</label>
-				<select id="style" bind:value={selectedStyleId} disabled={loading || !selectedCategoryId}>
+				<select id="style" bind:value={selectedStyleId} disabled={loading || !selectedCategoryId} data-umami-event="select_style">
 					{#if !selectedCategoryId}
 						<option value="">Select a category first...</option>
 					{:else if availableStyles.length === 0}
@@ -196,6 +213,7 @@
 					step="1"
 					bind:value={intensity}
 					disabled={loading}
+					data-umami-event="adjust_intensity"
 				/>
 				<span class="slider-end">Maximum</span>
 			</div>
@@ -240,7 +258,7 @@
 		</div>
 
 		<div class="prompt-section">
-			<button class="prompt-toggle" onclick={() => (showPrompt = !showPrompt)}>
+			<button class="prompt-toggle" onclick={() => (showPrompt = !showPrompt)} data-umami-event="toggle_prompt" data-umami-event-action={showPrompt ? 'close' : 'open'}>
 				{showPrompt ? '▼' : '▶'} Show prompt
 			</button>
 			{#if showPrompt}