FEATURE: allow persona to only force tool calls on limited replies (#827)

This introduces another configuration that allows operators to
limit the amount of interactions with forced tool usage.

Forced tools are very handy in initial llm interactions, but as
conversation progresses they can hinder by slowing down stuff
and adding confusion.

test/javascripts/unit/models/ai-persona-test.js

@@ -51,6 +51,7 @@ module("Discourse AI | Unit | Model | ai-persona", function () {
       question_consolidator_llm: "Question Consolidator LLM",
       allow_chat: false,
       tool_details: true,
+      forced_tool_count: -1,
     };
 
     const aiPersona = AiPersona.create({ ...properties });
@@ -92,6 +93,7 @@ module("Discourse AI | Unit | Model | ai-persona", function () {
       question_consolidator_llm: "Question Consolidator LLM",
       allow_chat: false,
       tool_details: true,
+      forced_tool_count: -1,
     };
 
     const aiPersona = AiPersona.create({ ...properties });