F3 (agent): mutate state.messages and state.pendingToolCalls in place on
appendMessage/popMessage/clearMessages/reset/tool_execution_start/_end
instead of allocating a fresh array/Set on every transition. Subscribers
that capture state.messages by reference now observe updates directly.
Public type signature unchanged.
F5 (ai): add parseStreamingJsonThrottled to utils/json-parse — a per-delta
wrapper around parseStreamingJson that skips the re-parse until the
buffer has grown by minGrowthBytes (default 256). Wired into every
provider's tool-call argument accumulator (anthropic, amazon-bedrock,
openai-completions, openai-codex-responses, openai-responses-shared) so
per-delta cost becomes O(N) in total buffer length instead of O(N²).
Every provider's toolcall_end still runs a final unthrottled parse, so
the published block.arguments is unchanged.
F8 (coding-agent): drop the per-delta structuredClone of streaming tool
arguments in ToolExecutionComponent.updateArgs. event-controller.ts and
ui-helpers.ts already spread their input into a fresh object on each
delta, so cloning here was dead work on the rendering hot path. Added a
reference-equality short-circuit so repeat calls with the same args
object skip the preview-diff and display refresh.
oldschoola