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/Models/ProjectRevision.php

@@ -0,0 +1,63 @@
+<?php
+
+namespace App\Models;
+
+use Database\Factories\ProjectRevisionFactory;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+
+class ProjectRevision extends Model
+{
+    /** @use HasFactory<ProjectRevisionFactory> */
+    use HasFactory;
+
+    public const STATUS_DRAFT = 'draft';
+
+    public const STATUS_APPROVED = 'approved';
+
+    public const STATUS_SUPERSEDED = 'superseded';
+
+    protected $fillable = [
+        'project_id', 'revision_number', 'change_notes', 'status', 'created_by',
+        'approved_by', 'approved_at', 'fusion_project_id', 'fusion_document_id', 'fusion_version',
+    ];
+
+    protected function casts(): array
+    {
+        return [
+            'approved_at' => 'datetime',
+        ];
+    }
+
+    public function project(): BelongsTo
+    {
+        return $this->belongsTo(Project::class);
+    }
+
+    public function creator(): BelongsTo
+    {
+        return $this->belongsTo(User::class, 'created_by');
+    }
+
+    public function approver(): BelongsTo
+    {
+        return $this->belongsTo(User::class, 'approved_by');
+    }
+
+    public function files(): HasMany
+    {
+        return $this->hasMany(ProjectFile::class, 'revision_id');
+    }
+
+    public function costSnapshots(): HasMany
+    {
+        return $this->hasMany(ProjectCostSnapshot::class, 'revision_id');
+    }
+
+    public function isApproved(): bool
+    {
+        return $this->status === self::STATUS_APPROVED;
+    }
+}