Add lead workflows, PDF signing, AR projects and photo gallery integration

GasTankAR/Views/AR/Projects/ARProjectsViewModel.swift

@@ -0,0 +1,55 @@
+import Foundation
+import Observation
+
+@MainActor @Observable
+final class ARProjectsViewModel {
+    private(set) var supplied: [ARProject] = []
+    private(set) var custom: [ARProject] = []
+    private(set) var isLoading = true
+    var errorMessage: String?
+    private let service: any ARProjectsProviding
+
+    init(service: any ARProjectsProviding) {
+        self.service = service
+    }
+
+    func load() {
+        isLoading = true
+        defer { isLoading = false }
+        do {
+            let projects = try service.loadProjects()
+            supplied = projects.filter { $0.source == .supplied }
+            custom = projects.filter { $0.source == .custom }
+        } catch { errorMessage = error.localizedDescription }
+    }
+
+    func update(id: UUID, name: String, tank: Tank) -> ARProject? {
+        do {
+            let project = try service.updateProject(id: id, name: name, tank: tank)
+            if let index = custom.firstIndex(where: { $0.id == id }) { custom[index] = project }
+            return project
+        } catch {
+            errorMessage = error.localizedDescription
+            return nil
+        }
+    }
+
+    func delete(id: UUID) {
+        do {
+            try service.deleteProject(id: id)
+            supplied.removeAll { $0.id == id }
+            custom.removeAll { $0.id == id }
+        } catch { errorMessage = error.localizedDescription }
+    }
+
+    func create(name: String, tank: Tank) -> ARProject? {
+        do {
+            let project = try service.createProject(name: name, tank: tank)
+            custom.insert(project, at: 0)
+            return project
+        } catch {
+            errorMessage = error.localizedDescription
+            return nil
+        }
+    }
+}