fix(ToolMap): remove static duplicate parameters handling in mapping openrouter

[Aldiwildan77]

Problem

ToolMap::map() contains two parameters keys in the same PHP array for the function definition:

'function' => [
    'name' => $tool->name(),
    'description' => $tool->description(),
    // KEY 1 (conditional spread)
    ...$tool->hasParameters() ? [
        'parameters' => (function () use ($tool): array {
            $properties = $tool->parametersAsArray();

            return [
                'type' => 'object',
                'properties' => $properties === [] ? new \stdClass : $properties,
                'required' => $tool->requiredParameters(),
            ];
        })(),
    ] : [],
    // KEY 2 (unconditional) — always overwrites KEY 1
    'parameters' => [
        'type' => 'object',
        'properties' => $tool->hasParameters() ? $tool->parametersAsArray() : (object) [],
        'required' => $tool->requiredParameters(),
    ],
],

In PHP, duplicate array keys cause the last one to win. This means:

1. KEY 1 is dead code — its output is always overwritten by KEY 2, including the stdClass empty-properties fallback that ensures correct JSON serialization as {} instead of []
2. Tools without parameters receive an unnecessary parameters block with { "properties": {}, "required": [] } because KEY 2 is unconditional — the hasParameters() check in KEY 1 never takes effect

Proof

A mock test confirms KEY 2 overwrites KEY 1. When hasParameters() is true and parametersAsArray() returns []:

• KEY 1 produces 'properties' => new \stdClass (serializes as JSON {})
• KEY 2 produces 'properties' => [] (serializes as JSON [])

With the buggy code, the result is [] — proving KEY 2 overwrote KEY 1.

Fix

Remove the unconditional duplicate parameters key (KEY 2). The conditional spread (KEY 1) already handles both cases correctly:

• hasParameters() === true → spreads parameters with proper schema and stdClass fallback
• hasParameters() === false → spreads nothing → no parameters key in output

Tests

Added 4 new tests (5 total, 18 assertions):

Test	What it proves
generates parameters only once from conditional spread	Mixed tools (with/without params) produce correct output — parameterized tools get schema, parameterless tools get no parameters key
proves parameters is generated by conditional spread not static duplicate	Uses a mock to verify properties is stdClass (from KEY 1), not [] (from KEY 2) — proving KEY 1 is now in control
sends correct tool payload to OpenRouter when streaming	End-to-end: verifies the actual HTTP request payload sent to OpenRouter via Http::assertSent — parameterless tools have no parameters in the request body
maps tools with strict mode	Existing — strict provider option still works correctly

Before / After

Before (tool without parameters):

{
  "type": "function",
  "function": {
    "name": "get_time",
    "description": "Returns the current time",
    "parameters": {
      "type": "object",
      "properties": {},
      "required": []
    }
  }
}

After (tool without parameters):

{
  "type": "function",
  "function": {
    "name": "get_time",
    "description": "Returns the current time"
  }
}

Test Check Result