Add text chunking and Persian language helpers

utils/chunker.py

@@ -0,0 +1,26 @@
+TG_LIMIT = 4096
+
+
+def chunk_text(text: str, max_length: int = TG_LIMIT) -> list[str]:
+    """Split text into ≤max_length chunks, preferring newline then space boundaries."""
+    if len(text) <= max_length:
+        return [text]
+
+    chunks: list[str] = []
+    while text:
+        if len(text) <= max_length:
+            chunks.append(text)
+            break
+
+        split_at = text.rfind('\n', 0, max_length)
+        if split_at == -1:
+            split_at = text.rfind(' ', 0, max_length)
+        if split_at == -1:
+            split_at = max_length
+
+        chunk = text[:split_at].strip()
+        if chunk:
+            chunks.append(chunk)
+        text = text[split_at:].strip()
+
+    return chunks