feat: confirmToolCall support — startToolCall with requireConfirmation + ToolRunnableCallable [JAR-9208]

[JoshParkSJ]

Changes

• Moves tool confirmation from the old interrupt-based flow to confirmToolCall on startToolCall:

1. Graph build — LangGraph's wrapping discards the original BaseTool reference; the typed subclass preserves .tool so the runtime can inspect it at init time (so we know which tools need confirmation before hitting the tool node and can pass require confirmation on startToolCall)
2. Runtime init — _get_tool_confirmation_info walks the compiled graph once, finds ConversationalToolRunnableCallable nodes, and builds a {tool_name: input_schema} lookup. This is needed because coded agents (create_agent) export a compiled graph as the only artifact — there's no side channel to pass confirmation metadata from the build step to the runtime.
3. Streaming — mapper checks the lookup on every AIMessage tool call, emits startToolCall with requireConfirmation: true and inputSchema.

• fixes AIMessageChunk self-accumulation bug that doubled tool names on the first streamed chunk (only triggered with OpenAI, not Claude); startToolCall now always emitted for confirmation tools
• rip-and-replace as we see zero production usage confirmed via App Insights telemetry (90 days)

Companion PRs

• AgentInterfaces#899 — CAS frontend
• uipath-python#1558 — confirmToolCall model + bridge
• uipath-runtime-python#104 — remove emit_interrupt_event
• uipath-agents-python#420 — skip HITL during eval

https://uipath.atlassian.net/browse/JAR-9208

[JoshParkSJ]

not a problem for low code agents, but might as well unify how we get tools requiring confirmation