feat(*): add RAG support

backend/src/bot/modules/ai/prompts.py

@@ -22,6 +22,39 @@ for example Group A: 1, Group A: 2a, Group B: 2b, etc.
 Or, Theory: 1, Theory: 2a, Practice: 1, etc.
 Only output identifiers that exist in the image."""
 
+
+RAGTHEORY_SYSTEM = """You help answer theoretical exam questions.
+
+When you receive an IMAGE with exam questions:
+1. Identify ALL questions/blanks to fill
+2. For EACH question, use search_knowledge_base to find relevant info
+3. Provide exam-ready answers
+
+OUTPUT FORMAT:
+- Number each answer matching the question number
+- Answer length: match what the question expects
+ (1 sentence, 1-2 sentences, fill blank, list items, etc.)
+- Write answers EXACTLY as they should appear on the exam sheet - ready to copy 1:1
+- Use precise terminology from the course
+- No explanations, no "because", no fluff - just the answer itself
+- For multi-part questions (a, b, c), answer each part separately
+
+LANGUAGE: Match the exam language (usually English for technical terms)
+
+STYLE: Academic, precise, minimal - as if you're writing on paper with limited space
+
+Example input:
+"Stigmergy is ............"
+Example output:
+"1. Stigmergy is indirect communication through environment\
+ modification, e.g. by leaving some marks."
+
+Example input:
+"How is crossing over performed in genetic programming? (one precise sentence)"
+Example output:
+"3. Usually implemented as swapping randomly selected subtrees of parent trees"
+"""
+
 DEFAULT_FOLLOW_UP = (
     "Based on the conversation, suggest 3 short follow-up questions "
     "the user might want to ask. Each option should be under 50 characters."
@@ -38,4 +71,7 @@ Summarize VERY briefly:
 
 Max 2-3 sentences. This is for Apple Watch display."""
 
-PRESETS: dict[str, tuple[str, str]] = {"exam": (EXAM_SYSTEM, EXAM_FOLLOW_UP)}
+PRESETS: dict[str, tuple[str, str]] = {
+    "exam": (EXAM_SYSTEM, EXAM_FOLLOW_UP),
+    "ragtheory": (RAGTHEORY_SYSTEM, EXAM_FOLLOW_UP),
+}