Add Video Projects schema and workflow engine core (tasks #31, #32)

Foundational layer for the YouTube Content Creation System project,
built as a fully independent domain per the earlier decision (task
#47) — no foreign keys into the existing projects/tasks/ideas tables.

Schema: video_projects, workflow_steps, assets, ai_providers,
workflow_templates (named to avoid colliding with the existing
Post-templates `templates` table).

WorkflowEngine (app/Support/VideoWorkflow/) drives a project's step
sequence: start/startFromTemplate, currentStep, completeStep (with
optional approval gating), approveStep/rejectStep, failStep/retryStep,
skipStep. It only manages state transitions — actual step execution
(AI calls, rendering, etc.) is out of scope here (tasks #33+).

Also fixes four Publisher classes (WordPress/Reddit/Twitter/LinkedIn)
that were missing a `use App\Models\SocialAccount;` import after an
earlier interface change, which broke the entire test suite at
bootstrap; and PostFactory, which still set the now-removed
`social_account_id` column instead of the SocialAccount pivot.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

database/factories/AiProviderFactory.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Database\Factories;
+
+use App\Models\AiProvider;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+class AiProviderFactory extends Factory
+{
+    protected $model = AiProvider::class;
+
+    public function definition(): array
+    {
+        return [
+            'name' => fake()->company().' Account',
+            'provider' => fake()->randomElement(AiProvider::PROVIDERS),
+            'api_key' => fake()->uuid(),
+            'is_active' => true,
+        ];
+    }
+}

database/factories/AssetFactory.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Database\Factories;
+
+use App\Models\Asset;
+use App\Models\VideoProject;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+class AssetFactory extends Factory
+{
+    protected $model = Asset::class;
+
+    public function definition(): array
+    {
+        return [
+            'video_project_id' => VideoProject::factory(),
+            'type' => fake()->randomElement(Asset::TYPES),
+            'disk_path' => 'video-projects/'.fake()->uuid().'.bin',
+            'mime_type' => 'application/octet-stream',
+            'size_bytes' => fake()->numberBetween(1000, 5_000_000),
+            'version' => 1,
+        ];
+    }
+}

database/factories/PostFactory.php

@@ -14,7 +14,6 @@ class PostFactory extends Factory
     {
         return [
             'site_id' => Site::factory(),
-            'social_account_id' => null,
             'type' => fake()->randomElement(Post::TYPES),
             'title' => fake()->optional()->sentence(),
             'body' => fake()->paragraph(),

database/factories/VideoProjectFactory.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Database\Factories;
+
+use App\Models\VideoProject;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+class VideoProjectFactory extends Factory
+{
+    protected $model = VideoProject::class;
+
+    public function definition(): array
+    {
+        return [
+            'title' => fake()->sentence(4),
+            'description' => fake()->optional()->paragraph(),
+            'status' => 'draft',
+        ];
+    }
+}

database/factories/WorkflowStepFactory.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace Database\Factories;
+
+use App\Models\VideoProject;
+use App\Models\WorkflowStep;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+class WorkflowStepFactory extends Factory
+{
+    protected $model = WorkflowStep::class;
+
+    public function definition(): array
+    {
+        return [
+            'video_project_id' => VideoProject::factory(),
+            'type' => fake()->randomElement(WorkflowStep::TYPES),
+            'order' => 0,
+            'status' => 'pending',
+            'requires_approval' => false,
+        ];
+    }
+}

database/factories/WorkflowTemplateFactory.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Database\Factories;
+
+use App\Models\WorkflowTemplate;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+class WorkflowTemplateFactory extends Factory
+{
+    protected $model = WorkflowTemplate::class;
+
+    public function definition(): array
+    {
+        return [
+            'name' => fake()->sentence(3),
+            'description' => fake()->optional()->sentence(),
+            'steps' => [
+                ['type' => 'script_generation', 'requires_approval' => true],
+                ['type' => 'tts_voiceover', 'requires_approval' => false],
+                ['type' => 'video_generation', 'requires_approval' => true],
+            ],
+        ];
+    }
+}

database/migrations/2026_08_06_203010_create_workflow_templates_table.php

@@ -0,0 +1,32 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::create('workflow_templates', function (Blueprint $table) {
+            $table->id();
+            $table->string('name');
+            $table->text('description')->nullable();
+            // Ordered array of step definitions, e.g.
+            // [{"type": "script_generation", "requires_approval": true}, ...]
+            $table->json('steps');
+            $table->timestamps();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('workflow_templates');
+    }
+};

database/migrations/2026_08_06_203011_create_video_projects_table.php

@@ -0,0 +1,36 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * Deliberately independent of the existing projects/tasks/ideas tables —
+     * no foreign keys into them. See Task #47 on the "YouTube Content
+     * Creation System" project for why.
+     */
+    public function up(): void
+    {
+        Schema::create('video_projects', function (Blueprint $table) {
+            $table->id();
+            $table->string('title');
+            $table->text('description')->nullable();
+            $table->string('status')->default('draft');
+            $table->foreignId('workflow_template_id')->nullable()->constrained()->nullOnDelete();
+            $table->softDeletes();
+            $table->timestamps();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('video_projects');
+    }
+};

database/migrations/2026_08_06_203012_create_workflow_steps_table.php

@@ -0,0 +1,39 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::create('workflow_steps', function (Blueprint $table) {
+            $table->id();
+            $table->foreignId('video_project_id')->constrained()->cascadeOnDelete();
+            $table->string('type');
+            $table->unsignedInteger('order');
+            $table->string('status')->default('pending');
+            $table->boolean('requires_approval')->default(false);
+            $table->json('input')->nullable();
+            $table->json('output')->nullable();
+            $table->text('error')->nullable();
+            $table->timestamp('started_at')->nullable();
+            $table->timestamp('completed_at')->nullable();
+            $table->timestamps();
+
+            $table->unique(['video_project_id', 'order']);
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('workflow_steps');
+    }
+};

database/migrations/2026_08_06_203013_create_assets_table.php

@@ -0,0 +1,35 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::create('assets', function (Blueprint $table) {
+            $table->id();
+            $table->foreignId('video_project_id')->constrained()->cascadeOnDelete();
+            $table->foreignId('workflow_step_id')->nullable()->constrained()->nullOnDelete();
+            $table->string('type');
+            $table->string('disk_path');
+            $table->string('mime_type')->nullable();
+            $table->unsignedBigInteger('size_bytes')->nullable();
+            $table->unsignedInteger('version')->default(1);
+            $table->json('metadata')->nullable();
+            $table->timestamps();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('assets');
+    }
+};

database/migrations/2026_08_06_203014_create_ai_providers_table.php

@@ -0,0 +1,32 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::create('ai_providers', function (Blueprint $table) {
+            $table->id();
+            $table->string('name');
+            $table->string('provider');
+            $table->string('api_key');
+            $table->json('config')->nullable();
+            $table->boolean('is_active')->default(true);
+            $table->timestamps();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('ai_providers');
+    }
+};