feat: stats and achievements (#45)

### Explanation

_No response_

### Issue

Closes #39

### Attestations

- [ ] I have read and agree to the [Code of Conduct](https://docs.nhcarrigan.com/community/coc/)
- [ ] I have read and agree to the [Community Guidelines](https://docs.nhcarrigan.com/community/guide/).
- [ ] My contribution complies with the [Contributor Covenant](https://docs.nhcarrigan.com/dev/covenant/).

### Dependencies

- [ ] I have pinned the dependencies to a specific patch version.

### Style

- [ ] I have run the linter and resolved any errors.
- [ ] My pull request uses an appropriate title, matching the conventional commit standards.
- [ ] My scope of feat/fix/chore/etc. correctly matches the nature of changes in my pull request.

### Tests

- [ ] My contribution adds new code, and I have added tests to cover it.
- [ ] My contribution modifies existing code, and I have updated the tests to reflect these changes.
- [ ] All new and existing tests pass locally with my changes.
- [ ] Code coverage remains at or above the configured threshold.

### Documentation

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### Versioning

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Reviewed-on: #45
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

src/routes/test-achievement/+page.svelte

@@ -0,0 +1,45 @@
+<script lang="ts">
+  import { testAchievementSound } from "$lib/sounds/achievement";
+  import { invoke } from "@tauri-apps/api/core";
+
+  async function testSound() {
+    testAchievementSound();
+  }
+
+  async function triggerAchievement() {
+    // This will trigger an achievement that hasn't been unlocked yet
+    try {
+      await invoke("check_achievements", {
+        eventType: "message_sent",
+        data: {},
+      });
+    } catch (error) {
+      console.error("Failed to trigger achievement:", error);
+    }
+  }
+</script>
+
+<div class="container mx-auto p-8">
+  <h1 class="text-2xl font-bold mb-6">Achievement Sound Test</h1>
+
+  <div class="space-y-4">
+    <button
+      onclick={testSound}
+      class="px-4 py-2 bg-blue-500 text-white rounded hover:bg-blue-600 transition-colors"
+    >
+      Test Achievement Sound
+    </button>
+
+    <button
+      onclick={triggerAchievement}
+      class="px-4 py-2 bg-green-500 text-white rounded hover:bg-green-600 transition-colors"
+    >
+      Trigger Test Achievement
+    </button>
+
+    <p class="text-sm text-gray-600 dark:text-gray-400 mt-4">
+      Click the first button to test just the sound effect.<br />
+      Click the second button to trigger a real achievement (if any are available to unlock).
+    </p>
+  </div>
+</div>