Freezmo: self-hosted notes-to-activities study app

Next.js 15 app that turns photos, PDFs, DOCX/PPTX and text into a swipeable
feed of AI-generated activities (flashcards, multiple choice, true/false,
fill-in-the-blank, matching, ordering, short answer) using the user's own
Ollama models.

Highlights:
- All AI calls run in server route handlers; the browser never talks to Ollama.
- Bring-your-own-key mode (default): the key lives only in the browser and is
  sent per-request; server, local-daemon and shared-key modes also supported.
- Client-side document extraction (pdf.js, mammoth, jszip) with scanned-PDF
  page rendering for the vision model; notes stay in their original language.
- ChatGPT-style shell: collapsible sidebar / mobile drawer, neutral token-based
  light + dark themes, folder organisation, PWA (manifest, SW, offline page).
- Strict JSON validation with zod + auto-repair, rate limiting, and request
  guards (cross-origin, body-size, API-key sanitising).
- setup.sh bootstraps deps, .env.local and a production build.

Gitignore excludes .env*, the generated pdf.js worker and local scratch files.

lib/use-health.ts

@@ -0,0 +1,39 @@
+"use client";
+
+import { useCallback, useEffect, useState, useSyncExternalStore } from "react";
+
+import { fetchHealth, type Health } from "./client-api";
+import { settingsStore } from "./settings";
+
+/**
+ * Health status for the current browser (re-checks whenever the API key
+ * changes). Used by the settings dialog and the "add your key" banner.
+ */
+export function useHealth() {
+  const apiKey = useSyncExternalStore(
+    settingsStore.subscribe,
+    () => settingsStore.getSnapshot().apiKey,
+    () => "",
+  );
+  const [health, setHealth] = useState<Health | null>(null);
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  const refresh = useCallback(async () => {
+    setLoading(true);
+    setError(null);
+    try {
+      setHealth(await fetchHealth());
+    } catch (loadError) {
+      setError(loadError instanceof Error ? loadError.message : "Could not reach the Freezmo server.");
+    } finally {
+      setLoading(false);
+    }
+  }, []);
+
+  useEffect(() => {
+    void refresh();
+  }, [refresh, apiKey]);
+
+  return { health, loading, error, refresh, apiKey };
+}