Add HL3D branding, Etsy Live/Draft paging and Projects lifecycle

Replace the old touchmark/PNG identity with the supplied lockup and
monogram, segmented role-aware navigation, Live/Draft listing filters
with generation-based cache invalidation, and admin Projects covering
immutable file revisions, listing live pointers, and exact-decimal
filament/packaging/shipping costing. Additive schema only; no Etsy
publication. Isolated clone tests: 301 tests, 1162 assertions.

app/Http/Controllers/ProjectFileController.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use App\Models\Project;
+use App\Models\ProjectFile;
+use Illuminate\Http\Request;
+use Illuminate\Support\Facades\Storage;
+use Symfony\Component\HttpFoundation\StreamedResponse;
+
+class ProjectFileController extends Controller
+{
+    public function download(Request $request, Project $project, ProjectFile $file): StreamedResponse
+    {
+        abort_unless($file->revision->project_id === $project->id, 404);
+        abort_unless($request->user()->can('download', [$file, $project]), 403);
+
+        return Storage::disk('project_files')->download($file->storage_key, $file->original_filename);
+    }
+}