ui: enable the agentic flow when only the JS sandbox is active

[ServeurpersoCom]

Overview

Enable the agentic infrastructure even when the browser-side JS sandbox is the only active tool source. The agentic gate counted MCP servers, builtin and custom tools but not frontend tools, so with the sandbox alone the flow was skipped, no tools field reached the server and the chat template rendered without the tool system prompt.

Additional information

Fixes #25856

Requirements

• I have read and agree with the contributing guidelines
• AI usage disclosure: NO

[rankaiyx]

Testing has confirmed that the issue has been resolved.

LGTM

<|im_start|>system
# Tools

You have access to the following functions:

<tools>
{"type": "function", "function": {"name": "run_javascript", "description": "Execute JavaScript in a sandboxed browser worker (no DOM, no page access). Top level await is supported. Use console.log to print intermediate values; a top level return statement is captured as the result.", "parameters": {"type": "object", "properties": {"code": {"type": "string", "description": "JavaScript source to execute"}, "timeout_ms": {"type": "number", "description": "Execution timeout in milliseconds, default 10000, max 30000"}}, "required": ["code"]}}}
</tools>

If you choose to call a function ONLY reply in the following format with NO suffix:<think>
Brief explanation of tool call
</think>
<tool_call>
<function=example_function_name>
<parameter=example_parameter_1>
value_1
</parameter>
<parameter=example_parameter_2>
This is the value for the second parameter
that can span
multiple lines
</parameter>
</function>
</tool_call>
<IMPORTANT>
Reminder:
- You can use the <think></think> block to plan your next tool call OR to synthesize data and formulate your final response to the user.
- ALL explanation and reasoning MUST be placed strictly inside the <think></think> block.- Function calls MUST follow the specified format: an inner <function=...></function> block must be nested within <tool_call></tool_call> XML tags.- If you choose to call a tool, you MUST output the <tool_call> block IMMEDIATELY after thinking, with NO conversational text before it.- The <tool_call> and <function> tags MUST be at the very beginning of a new line, with NO spaces or indentation before them.- To call multiple functions, output a separate, completely closed <tool_call></tool_call> block for EACH function. Do NOT nest <tool_call> blocks.
- If you have all necessary data, provide your final answer directly to the user without any tool call.
</IMPORTANT><|im_end|>