Add script/TTS step handlers, dashboard, and pipeline UI (#35, #36, #43, #44)

StepHandler abstraction (app/Support/VideoWorkflow/StepHandlers/) plugs
into WorkflowEngine without coupling it to how any given step type is
actually executed:
- ScriptGenerationHandler: builds a prompt from the project's title/
  description (or an explicit outline/tone/keywords/target length in
  step input), generates via an active OpenAI AiProvider, stores the
  result as a 'script' asset.
- TtsVoiceoverHandler: voices step.input.text, or falls back to the
  project's latest script asset, via an active ElevenLabs AiProvider;
  voice_id/model_id are configurable per step. No direct "speed"
  control — ElevenLabs' base TTS endpoint doesn't expose one.

RunWorkflowStepJob resolves a step's handler by type and runs it on
the queue, matching the existing PublishPostJob pattern (including a
stale-dispatch guard: no-op if the step isn't 'in_progress' anymore).

UI, under its own /video-projects routes and nav entry — separate
from /projects per the earlier decision:
- VideoProjects/Index (#43): list projects with status and step
  progress, create new ones.
- VideoProjects/Show (#44): start a project from a WorkflowTemplate or
  a hardcoded default 8-step pipeline; per-step Run/Approve/Reject/
  Retry/Skip actions; auto-queues the next step after any transition
  when a handler exists for its type (steps with no handler yet just
  sit in_progress rather than auto-failing); lists project assets.

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

app/Livewire/VideoProjects/Index.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace App\Livewire\VideoProjects;
+
+use App\Models\VideoProject;
+use Livewire\Attributes\Layout;
+use Livewire\Component;
+
+#[Layout('components.layouts.app')]
+class Index extends Component
+{
+    public bool $showForm = false;
+
+    public string $title = '';
+
+    public ?string $description = null;
+
+    public function render()
+    {
+        return view('livewire.video-projects.index', [
+            'projects' => VideoProject::withCount([
+                'steps',
+                'steps as completed_steps_count' => fn ($q) => $q->whereIn('status', ['completed', 'skipped']),
+            ])
+                ->with(['steps' => fn ($q) => $q->whereNotIn('status', ['completed', 'skipped'])->orderBy('order')->limit(1)])
+                ->orderByDesc('created_at')
+                ->get(),
+        ]);
+    }
+
+    public function create(): void
+    {
+        $this->title = '';
+        $this->description = null;
+        $this->resetValidation();
+        $this->showForm = true;
+    }
+
+    public function save(): void
+    {
+        $validated = $this->validate([
+            'title' => ['required', 'string', 'max:255'],
+            'description' => ['nullable', 'string'],
+        ]);
+
+        $project = VideoProject::create($validated);
+
+        $this->showForm = false;
+        $this->redirect(route('video-projects.show', $project), navigate: true);
+    }
+
+    public function delete(int $id): void
+    {
+        VideoProject::findOrFail($id)->delete();
+    }
+}