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/TOTPGeneratorTests.swift

@@ -0,0 +1,34 @@
+import XCTest
+@testable import KeeVaultCore
+
+final class TOTPGeneratorTests: XCTestCase {
+    // RFC 6238 Section 8 test vectors for SHA-1
+    // secret = "12345678901234567890" (ASCII), base32 = "GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQ"
+    let sha1Secret = "GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQ"
+
+    func test_sha1_at59s() {
+        let config = TOTPConfig(secret: sha1Secret, period: 30, digits: 8, algorithm: .sha1)
+        let date = Date(timeIntervalSince1970: 59)
+        XCTAssertEqual(TOTPGenerator.generate(config: config, at: date), "94287082")
+    }
+
+    func test_sha1_at1111111109s() {
+        let config = TOTPConfig(secret: sha1Secret, period: 30, digits: 8, algorithm: .sha1)
+        let date = Date(timeIntervalSince1970: 1111111109)
+        XCTAssertEqual(TOTPGenerator.generate(config: config, at: date), "07081804")
+    }
+
+    func test_secondsRemaining_isWithinPeriod() {
+        let config = TOTPConfig(secret: sha1Secret, period: 30)
+        let remaining = TOTPGenerator.secondsRemaining(config: config, at: Date())
+        XCTAssertGreaterThan(remaining, 0)
+        XCTAssertLessThanOrEqual(remaining, 30)
+    }
+
+    func test_generate_defaultSixDigits() {
+        let config = TOTPConfig(secret: sha1Secret)
+        let code = TOTPGenerator.generate(config: config, at: Date())
+        XCTAssertEqual(code.count, 6)
+        XCTAssertNotNil(Int(code))
+    }
+}