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.

KeeVaultCore/Tests/KeeVaultCoreTests/KDBXDocumentTests.swift

@@ -0,0 +1,36 @@
+import XCTest
+@testable import KeeVaultCore
+
+final class KDBXDocumentTests: XCTestCase {
+    var fixtureURL: URL!
+
+    override func setUp() {
+        super.setUp()
+        fixtureURL = Bundle.module.url(forResource: "test", withExtension: "kdbx", subdirectory: "Fixtures")!
+    }
+
+    func test_read_parsesRootGroup() throws {
+        let doc = KDBXDocument(url: fixtureURL)
+        let db = try doc.read(password: "1234")
+        XCTAssertFalse(db.root.name.isEmpty)
+    }
+
+    func test_read_wrongPassword_throwsInvalidPassword() throws {
+        let doc = KDBXDocument(url: fixtureURL)
+        XCTAssertThrowsError(try doc.read(password: "wrong")) { error in
+            XCTAssertEqual(error as? KDBXError, .invalidPassword)
+        }
+    }
+
+    func test_roundTrip_preservesEntryTitle() throws {
+        let doc = KDBXDocument(url: fixtureURL)
+        var db = try doc.read(password: "1234")
+        let newEntry = Entry(title: "RoundTripTest", username: "user", password: ProtectedString("pass"))
+        db.root.entries.append(newEntry)
+        let tmpURL = FileManager.default.temporaryDirectory.appendingPathComponent("roundtrip.kdbx")
+        let tmpDoc = KDBXDocument(url: tmpURL)
+        try tmpDoc.write(db, password: "1234")
+        let reloaded = try KDBXDocument(url: tmpURL).read(password: "1234")
+        XCTAssertTrue(reloaded.root.entries.contains { $0.title == "RoundTripTest" })
+    }
+}