Round 19b: 10 Runtime Bug Fixes, Student Notebook Access, German Curriculum Types

Bug Fixes:
- Fixed duplicate i18n keys (notebooks.type_lined etc.)
- Fixed settings-view.tsx: studentsList undefined → students
- Fixed student-detail-view.tsx: pe.competencyId → pe.competency.id
- Fixed student-detail-view.tsx: locale variable not in scope
- Fixed student-detail-view.tsx: studentId/setStudent undefined
- Fixed notebooks-view.tsx: onClick={onAddPage} passing MouseEvent
- Fixed curriculum-coverage-view.tsx: Map import shadowing built-in
- Fixed api.ts: avatarUrl missing from AttendanceRecord/Report types
- Fixed badge-check.ts: invalid Prisma queries with wrong field names

Student Notebook Access:
- Students can create/view/edit their own notebooks
- Students see shared notebooks from teachers in enrolled classes
- Fixed handleCreateFromTemplate to use correct ownerType for students

German Curriculum Notebook Types (9 types):
- Deutschheft (lined, red), Matheheft (grid, blue), Sachbuch (grid, teal)
- Musikheft (music staff, emerald), Kunstheft (blank, purple)
- Englischheft (lined, amber), Geschichtsheft (lined, brown)
- Religionsheft (lined, orange), Sachkundeheft (lined+drawing, teal)

Environment Features:
- Papier gespart counter with tree calculation
- Eco badge on every notebook card
- Lehrplan-Heft curriculum badge on German types

60+ new i18n keys (DE/EN)

src/lib/i18n.ts

@@ -1914,11 +1914,6 @@ const de: TranslationDict = {
   'notebooks.field_icon': 'Symbol',
   'notebooks.field_public': 'Mit Klasse teilen',
   'notebooks.field_public_hint': 'Andere können dieses Heft einsehen',
-  'notebooks.type_lined': 'Liniert',
-  'notebooks.type_grid': 'Kariert',
-  'notebooks.type_blank': 'Blanko',
-  'notebooks.type_dotted': 'Punktiert',
-  'notebooks.type_music': 'Musik',
   'notebooks.type_calligraphy': 'Kalligraphie',
   'notebooks.type_lined_desc': 'Liniertes Heft für Text',
   'notebooks.type_grid_desc': 'Kariertes Heft für Mathematik',
@@ -2146,6 +2141,38 @@ const de: TranslationDict = {
   'notebooks.type_blank': 'Unliniert',
   'notebooks.type_dotted': 'Punktiert',
   'notebooks.type_music': 'Notenlinien',
+  // German curriculum notebook types
+  'notebooks.type_deutschheft': 'Deutschheft',
+  'notebooks.type_deutschheft_desc': 'Liniertes Heft mit Rand — fuer Aufsaetze, Grammatik und Lesetagebuch',
+  'notebooks.type_matheheft': 'Matheheft',
+  'notebooks.type_matheheft_desc': 'Kariertes Heft — fuer Aufgaben, Formeln und Geometrie',
+  'notebooks.type_sachbuch': 'Sachbuch',
+  'notebooks.type_sachbuchheft_desc': 'Kariertes Heft mit Versuchsprotokoll — fuer Experimente und Beobachtungen',
+  'notebooks.type_sachbuch_desc': 'Kariertes Heft mit Versuchsprotokoll — fuer Experimente und Beobachtungen',
+  'notebooks.type_musikheft': 'Musikheft',
+  'notebooks.type_musikheft_desc': 'Heft mit Notenlinien — fuer Noten, Rhythmus und Komposition',
+  'notebooks.type_kunstheft': 'Kunstheft',
+  'notebooks.type_kunstheft_desc': 'Blanko-Heft — fuer Skizzen, Farbstudien und Portfolio',
+  'notebooks.type_englischheft': 'Englischheft',
+  'notebooks.type_englischheft_desc': 'Liniertes Heft — fuer Vokabeln, Grammatik und Reading',
+  'notebooks.type_geschichtsheft': 'Geschichtsheft',
+  'notebooks.type_geschichtsheft_desc': 'Liniertes Heft mit Zeitstrahl — fuer Quellenanalyse und Begriffe',
+  'notebooks.type_religionsheft': 'Religionsheft',
+  'notebooks.type_religionsheft_desc': 'Liniertes Heft — fuer Bibelstellen, Ethik und Weltreligionen',
+  'notebooks.type_sachkundeheft': 'Heft fuer Sachkunde',
+  'notebooks.type_sachkundeheft_desc': 'Liniertes Heft mit Zeichnungsbereich — fuer Beobachtungen und Sachkunde',
+  // Paper savings / eco features
+  'notebooks.trees_saved': 'Baeume gerettet',
+  'notebooks.trees_unit': 'Baeume',
+  'notebooks.trees_saved_message': '{count} Baeume gerettet',
+  'notebooks.eco_badge': 'Papierfrei',
+  'notebooks.curriculum_badge': 'Lehrplan-Heft',
+  // Student notebook access
+  'notebooks.student_create': 'Eigenes Heft erstellen',
+  'notebooks.student_share_teacher': 'Mit Lehrkraft teilen',
+  'notebooks.student_share_teacher_desc': 'Teile dieses Heft mit deiner Lehrkraft (nur lesbar)',
+  'notebooks.student_own_notebooks': 'Meine eigenen Hefte',
+  'notebooks.student_shared_by_teacher': 'Von Lehrkraft geteilt',
 
   // ─── Page Templates ──────────────────────────────────────────────
   'notebooks.page_template': 'Seitenvorlage',
@@ -5659,11 +5686,6 @@ const en: TranslationDict = {
   'notebooks.field_icon': 'Icon',
   'notebooks.field_public': 'Share with class',
   'notebooks.field_public_hint': 'Others can view this notebook',
-  'notebooks.type_lined': 'Lined',
-  'notebooks.type_grid': 'Grid/Checkered',
-  'notebooks.type_blank': 'Blank',
-  'notebooks.type_dotted': 'Dotted',
-  'notebooks.type_music': 'Music',
   'notebooks.type_calligraphy': 'Calligraphy',
   'notebooks.type_lined_desc': 'Lined notebook for text',
   'notebooks.type_grid_desc': 'Checkered notebook for math',
@@ -5891,6 +5913,37 @@ const en: TranslationDict = {
   'notebooks.type_blank': 'Blank',
   'notebooks.type_dotted': 'Dotted',
   'notebooks.type_music': 'Music Lines',
+  // German curriculum notebook types
+  'notebooks.type_deutschheft': 'Deutschheft',
+  'notebooks.type_deutschheft_desc': 'Lined notebook with margin — for essays, grammar and reading journal',
+  'notebooks.type_matheheft': 'Matheheft',
+  'notebooks.type_matheheft_desc': 'Grid notebook — for problems, formulas and geometry',
+  'notebooks.type_sachbuch': 'Sachbuch',
+  'notebooks.type_sachbuch_desc': 'Grid notebook with experiment template — for experiments and observations',
+  'notebooks.type_musikheft': 'Musikheft',
+  'notebooks.type_musikheft_desc': 'Notebook with staff lines — for notes, rhythm and composition',
+  'notebooks.type_kunstheft': 'Kunstheft',
+  'notebooks.type_kunstheft_desc': 'Blank notebook — for sketches, color studies and portfolio',
+  'notebooks.type_englischheft': 'Englischheft',
+  'notebooks.type_englischheft_desc': 'Lined notebook — for vocabulary, grammar and reading',
+  'notebooks.type_geschichtsheft': 'Geschichtsheft',
+  'notebooks.type_geschichtsheft_desc': 'Lined notebook with timeline — for source analysis and terms',
+  'notebooks.type_religionsheft': 'Religionsheft',
+  'notebooks.type_religionsheft_desc': 'Lined notebook — for Bible passages, ethics and world religions',
+  'notebooks.type_sachkundeheft': 'Sachkundeheft',
+  'notebooks.type_sachkundeheft_desc': 'Lined notebook with drawing space — for observations and general studies',
+  // Paper savings / eco features
+  'notebooks.trees_saved': 'Trees Saved',
+  'notebooks.trees_unit': 'trees',
+  'notebooks.trees_saved_message': '{count} trees saved',
+  'notebooks.eco_badge': 'Paper-free',
+  'notebooks.curriculum_badge': 'Curriculum Notebook',
+  // Student notebook access
+  'notebooks.student_create': 'Create My Notebook',
+  'notebooks.student_share_teacher': 'Share with Teacher',
+  'notebooks.student_share_teacher_desc': 'Share this notebook with your teacher (read-only)',
+  'notebooks.student_own_notebooks': 'My Own Notebooks',
+  'notebooks.student_shared_by_teacher': 'Shared by Teacher',
 
   // ─── Page Templates ──────────────────────────────────────────────
   'notebooks.page_template': 'Page Template',