added RAG, Multiuser, TG bot

backend/app/rag/chunker.py

@@ -0,0 +1,20 @@
+from __future__ import annotations
+
+
+def chunk_text(text: str, *, chunk_size: int = 800, overlap: int = 120) -> list[str]:
+    cleaned = (text or "").strip()
+    if not cleaned:
+        return []
+    if len(cleaned) <= chunk_size:
+        return [cleaned]
+    chunks: list[str] = []
+    start = 0
+    while start < len(cleaned):
+        end = min(len(cleaned), start + chunk_size)
+        piece = cleaned[start:end].strip()
+        if piece:
+            chunks.append(piece)
+        if end >= len(cleaned):
+            break
+        start = max(0, end - overlap)
+    return chunks