Non-streaming /api/chat support including:
- Vision via images: []base64
- Tool calls on assistant + tool-role response messages
- think field accepting string reasoning levels (or "true"/"false")
- Authorization header when apiKey is non-empty (cloud mode)
Tool-call arguments are passed as JSON objects to the wire and surfaced
as JSON-string Arguments on provider.ToolCall. Tool calls are assigned
synthetic IDs (tc_<index>) when Ollama omits one, so the round-trip
back as an assistant tool_calls + tool-role message remains correlated.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
