The `save_to_memory` function works by saving content to persistent vector memory
in ChromaDB. It uses tree-sitter for code parsing for supported file types:
.py, .js, .ts, .css, .html, and .md. Other formats fall back on DeepSeek/Ollama
LLM summarization. It uses deterministic md5 IDs so re-scans overwrite duplicates
and logs token usage to `zerikai.db`.

Sources: main.py:1072, README.md:279, code_indexer.py:169, code_indexer.py:204,
code_indexer.py:30