Fix Browse button (#3) and missing-canvasapi pipeline crash (#4)

#3: Browse button on Settings page → Output Directory had no effect.
loadSettingsData() injects the Browse button into #conn-fields
asynchronously, but attachPageHandlers tried to bind the click handler
before the element existed. The optional chaining (?.) silently no-op'd.
Fix: await loadSettingsData() before binding handlers on page 6.

#4: Pipeline failed with "No module named 'canvasapi'" because env:check
only verified tqdm/requests/openai imports, missing several core deps that
downloader.py and other pipeline scripts need. Users could pass the first-
start wizard with a partially-installed venv and hit the cryptic crash
mid-pipeline. Fix: extend the env:check import probe to cover canvasapi,
PIL, fitz, pptx; also re-run checkEnv from the renderer right before
launching the pipeline so a regressed venv prompts the user to reinstall
instead of failing silently.

Verified: 26/26 jest tests pass; node --check on main.js and app.js clean.

Author: nodeeeeee

electron/main.js

@@ -984,15 +984,19 @@ function registerIpc() {
     path: VENV_PYTHON,
   }));
 
-  // Environment readiness check for first-start wizard
+  // Environment readiness check for first-start wizard.
+  // Imports cover everything downloader.py and the other pipeline scripts
+  // need at start-up. Missing any of these triggers the setup wizard so the
+  // user installs the ML environment instead of hitting "No module named X"
+  // mid-pipeline (e.g. issue #4: canvasapi missing).
   ipcMain.handle('env:check', () => {
     const hasPython = fs.existsSync(VENV_PYTHON);
-    // Check if core packages are importable
     let coreOk = false;
     if (hasPython) {
       try {
-        const r = spawnSync(VENV_PYTHON, ['-c', 'import tqdm, requests, openai; print("ok")'],
-                            { timeout: 10000, windowsHide: true });
+        const r = spawnSync(VENV_PYTHON,
+          ['-c', 'import tqdm, requests, openai, canvasapi, PIL, fitz, pptx; print("ok")'],
+          { timeout: 10000, windowsHide: true });
         coreOk = (r.status === 0 && (r.stdout || '').toString().includes('ok'));
       } catch {}
     }

electron/renderer/app.js

@@ -1460,6 +1460,18 @@ async function attachPageHandlers() {
     document.getElementById('pp-run-btn')?.addEventListener('click', async () => {
       const cid     = document.getElementById('pp-course')?.value;
       if (!cid) { snack('Select a course first.', false); return; }
+
+      // Verify the ML environment is ready before launching Python.
+      // Without this, missing imports (e.g. canvasapi — issue #4) surface
+      // as a cryptic mid-pipeline failure.
+      try {
+        const env = await window.api.checkEnv();
+        if (env && env.needsSetup) {
+          snack('ML environment not installed. Open Settings → Install ML Environment.', false);
+          return;
+        }
+      } catch {/* checkEnv unavailable in older builds — proceed */}
+
       const python  = await window.api.getPythonPath();
       const outDir  = State.outputDir || await window.api.getOutputDir();
       const stealth = document.getElementById('pp-stealth')?.checked;
@@ -1749,7 +1761,10 @@ async function attachPageHandlers() {
 
   // ── Settings ──────────────────────────────────────────────────────────────────
   if (pg === 6) {
-    loadSettingsData();
+    // loadSettingsData injects the Browse button + other inputs into
+    // #conn-fields asynchronously. Await it before binding handlers, otherwise
+    // the elements don't exist yet and the bindings silently no-op.
+    await loadSettingsData();
     fillEnvComponents();
 
     document.getElementById('cfg-browse-btn')?.addEventListener('click', async () => {