fix: gebruik theme_session_completions voor learnDone op dashboard

getLearnDone was een deprecated stub die altijd false teruggaf nadat
de learn_progress-collectie is gedropt. Hierdoor toonde het dashboard
permanent 'Complete your theme session first', zelfs als de theme
session al voltooid was, en werd cycle progress nooit opgeteld.

Alle drie call-sites vervangen door getThemeSessionCompletion (de
huidige bron van waarheid), en de dode stubs verwijderd uit db.js.

Closes #9

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/curriculumService.js

@@ -350,7 +350,7 @@ export async function getYearProgress(userId, personalWeekNumber) {
   
   let completed = 0;
   for (let w = cycleStartWeek; w <= cycleEndWeek; w++) {
-    const done = await db.getLearnDone(userId, w);
+    const done = await db.getThemeSessionCompletion(userId, w);
     if (done) completed++;
   }
   

src/lib/db.js

@@ -326,13 +326,6 @@ export function setCachedQuiz(userId, weekNumber, quiz) {
   return Promise.resolve(quiz);
 }
 
-// ── Learn Progress (DEPRECATED — collection dropped) ────────────────────────
-
-/** @deprecated learn_progress collection has been dropped. */
-export async function getLearnDone() { return false; }
-/** @deprecated learn_progress collection has been dropped. */
-export async function setLearnDone() { return null; }
-
 // ── Theme Sessions ──────────────────────────────────────────────────────────
 
 /**

src/pages/Dashboard.jsx

@@ -31,13 +31,14 @@ const Dashboard = () => {
     if (!currentUser) return;
 
     const load = async () => {
-      const [topic, learnDone, testResult, allUsers, leaderboard] = await Promise.all([
+      const [topic, learnCompletion, testResult, allUsers, leaderboard] = await Promise.all([
         getAssignedTopic(currentUser.id, weekNumber),
-        db.getLearnDone(currentUser.id, weekNumber),
+        db.getThemeSessionCompletion(currentUser.id, weekNumber),
         db.getQuizResult(currentUser.id, weekNumber),
         db.getTeamMembers(),
         db.getLeaderboard(),
       ]);
+      const learnDone = !!learnCompletion;
 
       const nonAdminIds = allUsers.filter(u => u.role !== 'admin').map(u => u.id);
       const filtered = leaderboard.filter(u => nonAdminIds.includes(u.user_id));
@@ -48,7 +49,7 @@ const Dashboard = () => {
       const activity = [];
       for (let w = weekNumber; w >= Math.max(1, weekNumber - 3); w--) {
         const [pastLearn, pastTest, pastTopic] = await Promise.all([
-          db.getLearnDone(currentUser.id, w),
+          db.getThemeSessionCompletion(currentUser.id, w),
           db.getQuizResult(currentUser.id, w),
           getAssignedTopic(currentUser.id, w),
         ]);