feat(geom9 ch3 wave2 + final): §12 «Герон» + Финал Главы 3

backend/src/server.js

@@ -51,6 +51,7 @@ const collectionRoutes    = require('./routes/collection');
 const redBookRoutes       = require('./routes/red-book');
 const parentRoutes        = require('./routes/parent');
 const exam9Routes         = require('./routes/exam9');
+const examPrepRoutes      = require('./routes/exam-prep');
 const textbookRoutes      = require('./routes/textbooks');
 const teacherStudentsRoutes = require('./routes/teacherStudents');
 
@@ -171,6 +172,7 @@ app.use('/api/red-book',     requireFeature('red_book'),      redBookRoutes);
 app.use('/api/biochem',      requireFeature('biochem'),       require('./routes/biochem'));
 app.use('/api/parent',       parentRoutes);
 app.use('/api/exam9',        exam9Routes);
+app.use('/api/exam-prep',    examPrepRoutes);
 app.use('/api/textbooks',    textbookRoutes);
 app.use('/api/teacher-students', teacherStudentsRoutes);
 
@@ -340,6 +342,34 @@ app.get('/textbooks', (_req, res) => {
   res.sendFile(path.join(frontendDir, 'textbooks.html'));
 });
 
+// ── Exam preparation module: /exam-prep/:examKey/{,variants,practice,topics,mock}[/...]
+// All sub-pages share the same examKey segment; sub-view is the second segment.
+// The HTML file is chosen by the sub-view; examKey is parsed client-side from URL.
+function sendExamPrep(res, file) {
+  if (!isProd) res.setHeader('Cache-Control', 'no-store');
+  res.sendFile(path.join(frontendDir, file));
+}
+const EXAM_PREP_VIEWS = {
+  variants: 'exam-prep-variants.html',
+  practice: 'exam-prep-practice.html',
+  topics:   'exam-prep-topics.html',
+  mock:     'exam-prep-mock.html',
+};
+// /exam-prep → redirect to default track (math9 for now)
+app.get('/exam-prep', (_req, res) => res.redirect(302, '/exam-prep/math9'));
+// /exam-prep/:examKey → dashboard
+app.get('/exam-prep/:examKey', (_req, res) => sendExamPrep(res, 'exam-prep.html'));
+// /exam-prep/:examKey/:view → corresponding sub-page (sub-view + optional trailing segments)
+app.get(['/exam-prep/:examKey/:view', '/exam-prep/:examKey/:view/*'], (req, res, next) => {
+  const file = EXAM_PREP_VIEWS[req.params.view];
+  if (!file) return next();
+  sendExamPrep(res, file);
+});
+
+// NOTE: /exam9 remains live (served by static middleware as exam9.html) until F2
+// ports the variant browser into /exam-prep/:examKey/variants. The 301 redirect
+// will be added at that point.
+
 // Serve HTML files without extension  (/dashboard → dashboard.html)
 // In dev: disable cache so edits are always picked up immediately
 const htmlCacheOpts = isProd ? { extensions: ['html'] } : {