feat: copper accent theme, always-expanded group filter, app icon; rename MyPass to KeeVault

- Custom copper AccentColor and warm VaultBackground color assets (light/dark),
  applied to both the main app and the AutoFill extension (which needed its own
  copy of the asset catalog plus ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME
  and an explicit .tint() modifier, since extensions don't pick up the app-wide
  accent color the same way a full SwiftUI App/Scene does).
- GroupFilterView no longer uses DisclosureGroup for subgroups -- the whole tree
  renders always-expanded (indented per depth) so active filters are visible at
  a glance instead of requiring tap-to-expand.
- Added a placeholder app icon (padlock glyph, light/dark/tinted variants plus
  macOS sizes) -- previously the icon slot existed but had no actual images,
  which blocks App Store/TestFlight archive validation.
- Added ITSAppUsesNonExemptEncryption = NO (standard encryption only, via
  KeePassKit) to skip the export-compliance prompt on each upload.
- Renamed the app from MyPass to KeeVault throughout: Xcode project/targets/
  schemes, the MyPassCore package (now KeeVaultCore) and every import site,
  folder and file names, bundle identifiers (org.antiloop222.keevault) and
  their App Group/Keychain-group entitlements, and remaining UI/string
  references -- MyPass was already taken as an App Store app name.

KeeVault/Services/ClipboardService.swift

@@ -0,0 +1,30 @@
+//
+//  ClipboardService.swift
+//  KeeVault
+//
+
+import Foundation
+#if os(iOS)
+import UIKit
+#else
+import AppKit
+#endif
+
+public enum ClipboardService {
+    public static func copy(_ text: String, expiresAfter seconds: TimeInterval = 30) {
+        #if os(iOS)
+        UIPasteboard.general.setItems(
+            [[UIPasteboard.typeAutomatic: text]],
+            options: [.expirationDate: Date().addingTimeInterval(seconds)]
+        )
+        #else
+        let pb = NSPasteboard.general
+        pb.clearContents()
+        pb.setString(text, forType: .string)
+        let captured = text
+        DispatchQueue.main.asyncAfter(deadline: .now() + seconds) {
+            if pb.string(forType: .string) == captured { pb.clearContents() }
+        }
+        #endif
+    }
+}