feat: Generation Page AI workflows + AI/Vector modules + exam session fixes

Generation Page (complete rebuild):
- Full production-parity exam generation wizard with 4 IELTS modules
- Reading: AI passage gen, 5 exercise types (MCQ, Fill, Write, T/F, Match)
- Listening: 4 section types, AI context gen, TTS audio gen (ElevenLabs)
- Writing: Task 1/2, AI instruction gen, word limits, marks
- Speaking: 3 parts, AI script gen, avatar video gen (7 avatars)
- Per-module config: timer, CEFR difficulty, access, approval, rubrics
- Exam submission workflow (draft/published)

Exam Structures:
- New encoach.exam.structure model + CRUD controller
- ExamStructuresPage wired to real API

AI Module (encoach_ai):
- OpenAI service, ElevenLabs TTS, AWS Polly, ELAI avatars
- AI settings model with Odoo config parameters
- 7 generation endpoints (passage, exercises, instructions, scripts, context)

Vector Module (encoach_vector):
- pgvector integration for RAG-based content search
- Embedding service with sentence-transformers

Exam Session Fixes:
- Fixed ExamSession.tsx field mapping (question_type→type, exam_title→title)
- Fixed submit payload to include attempt_id and answers
- Fixed normalizeType to handle null/undefined

Tested: 12/12 API tests passed, browser-verified with real OpenAI calls
Made-with: Cursor

src/pages/RecordPage.tsx

@@ -21,9 +21,9 @@ export default function RecordPage() {
         <p className="text-muted-foreground">Browse assignment and exam attempt history.</p>
       </div>
 
-      <AiTipBanner tip="The student's scores show an upward trend from 5.5 → 6.0 → 7.5 over the last 3 completed exams. Listening remains the weakest module — recommend targeted practice." variant="insight" />
+      <AiTipBanner context="record" variant="insight" />
 
-      <AiReportNarrative narrative="3 of 4 attempts completed with an average score of 6.3. Time management is good — all exams finished within allocated time. The Full Mock Exam is still in progress (67% time used). Strongest area: Reading (7.5), weakest: Listening (5.5)." />
+      <AiReportNarrative report_type="record" data={{ records }} />
 
       <div className="flex flex-wrap gap-3 items-center">
         <Select><SelectTrigger className="w-[160px]"><SelectValue placeholder="Entity" /></SelectTrigger>