ChatAdapter concrete base class.
Concrete base class for chat format adapters (80% logic).
ChatAdapter(std::string tier_name, std::string identity_prompt)
Construct adapter with tier identity.
Gemma 4 chat adapter (covers A4B / E4B / E2B variants).
std::string chat_format() const override
Chat format: GGUF-embedded template.
ParseResult parse_tool_calls(const std::string &content) const override
Parse tool calls via tagged JSON, falling back to bare JSON.
Activate model on GPU (WARM → ACTIVE).
Parsed tool call result: cleaned content + extracted calls.