Add AI usage logs for Gemini and Whisper

- Migration + AiUsageLog model with tokens, duration, time, cost fields
- GeminiIntentService and GeminiVisionService log every API call
  with input/output token counts from usageMetadata and response time
- TelegramBotService logs Whisper calls with audio duration (from Telegram)
  and calculates cost at $1/second
- Whisper voice duration now passed from TelegramWebhookController
- Free text in Telegram now tries Gemini intent detection before showing menu
- /chat/ia-logs: Livewire component with summary cards + filterable table
- Whisper connection test button in config panel
- "Logs IA" link added to Chat/Bot nav section

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

database/migrations/2026_07_14_000001_create_ai_usage_logs_table.php

@@ -0,0 +1,34 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::create('ai_usage_logs', function (Blueprint $table) {
+            $table->id();
+            $table->string('servicio', 30);
+            $table->string('canal', 20)->default('telegram');
+            $table->unsignedBigInteger('usuario_id')->nullable();
+            $table->integer('input_tokens')->nullable();
+            $table->integer('output_tokens')->nullable();
+            $table->integer('audio_segundos')->nullable();
+            $table->integer('tiempo_ms')->default(0);
+            $table->decimal('costo', 10, 2)->default(0);
+            $table->string('resultado', 10)->default('ok');
+            $table->text('detalle')->nullable();
+            $table->timestamps();
+
+            $table->index(['servicio', 'created_at']);
+            $table->index('usuario_id');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::dropIfExists('ai_usage_logs');
+    }
+};