Add comprehensive iOS unit and UI test suites for greenfield test plan

- Create unit tests: DataLayerTests (27 tests for DATA-001–007), DataManagerExtendedTests
  (20 tests for TASK-005, TASK-012, TCOMP-003, THEME-001, QA-002), plus ValidationHelpers,
  TaskMetrics, StringExtensions, DoubleExtensions, DateUtils, DocumentHelpers, ErrorMessageParser
- Create UI tests: AuthenticationTests, PasswordResetTests, OnboardingTests, TaskIntegration,
  ContractorIntegration, ResidenceIntegration, DocumentIntegration, DataLayer, Stability
- Add UI test framework: AuthenticatedTestCase, ScreenObjects, TestFlows, TestAccountManager,
  TestAccountAPIClient, TestDataCleaner, TestDataSeeder
- Add accessibility identifiers to password reset views for UI test support
- Add greenfield test plan CSVs and update automated column for 27 test IDs
- All 297 unit tests pass across 60 suites

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

iosApp/CaseraTests/StringExtensionsTests.swift

@@ -0,0 +1,203 @@
+//
+//  StringExtensionsTests.swift
+//  CaseraTests
+//
+//  Unit tests for String and Optional<String> extensions.
+//
+
+import Testing
+@testable import Casera
+
+// MARK: - isBlank Tests
+
+struct IsBlankTests {
+
+    @Test func emptyStringIsBlank() {
+        #expect("".isBlank)
+    }
+
+    @Test func whitespaceOnlyIsBlank() {
+        #expect("   ".isBlank)
+    }
+
+    @Test func nonEmptyIsNotBlank() {
+        #expect(!"hello".isBlank)
+    }
+
+    @Test func stringWithWhitespacePaddingIsNotBlank() {
+        #expect(!" hello ".isBlank)
+    }
+}
+
+// MARK: - nilIfBlank Tests
+
+struct NilIfBlankTests {
+
+    @Test func emptyReturnsNil() {
+        #expect("".nilIfBlank == nil)
+    }
+
+    @Test func whitespaceOnlyReturnsNil() {
+        #expect("   ".nilIfBlank == nil)
+    }
+
+    @Test func nonEmptyReturnsTrimmed() {
+        #expect(" hello ".nilIfBlank == "hello")
+    }
+
+    @Test func plainStringReturnsSelf() {
+        #expect("test".nilIfBlank == "test")
+    }
+}
+
+// MARK: - capitalizedFirst Tests
+
+struct CapitalizedFirstTests {
+
+    @Test func lowercaseFirstCapitalized() {
+        #expect("hello".capitalizedFirst == "Hello")
+    }
+
+    @Test func alreadyCapitalizedUnchanged() {
+        #expect("Hello".capitalizedFirst == "Hello")
+    }
+
+    @Test func allUppercaseOnlyFirstKept() {
+        #expect("hELLO".capitalizedFirst == "HELLO")
+    }
+
+    @Test func emptyStringReturnsEmpty() {
+        #expect("".capitalizedFirst == "")
+    }
+
+    @Test func singleCharCapitalized() {
+        #expect("a".capitalizedFirst == "A")
+    }
+}
+
+// MARK: - truncated Tests
+
+struct TruncatedTests {
+
+    @Test func shortStringNotTruncated() {
+        #expect("hi".truncated(to: 10) == "hi")
+    }
+
+    @Test func longStringTruncatedWithEllipsis() {
+        #expect("Hello World".truncated(to: 5) == "Hello...")
+    }
+
+    @Test func longStringTruncatedWithoutEllipsis() {
+        #expect("Hello World".truncated(to: 5, addEllipsis: false) == "Hello")
+    }
+
+    @Test func exactLengthNotTruncated() {
+        #expect("Hello".truncated(to: 5) == "Hello")
+    }
+}
+
+// MARK: - isValidEmail Tests
+
+struct IsValidEmailTests {
+
+    @Test func standardEmailValid() {
+        #expect("user@example.com".isValidEmail)
+    }
+
+    @Test func emailWithSubdomainValid() {
+        #expect("user@mail.example.com".isValidEmail)
+    }
+
+    @Test func emailWithPlusValid() {
+        #expect("user+tag@example.com".isValidEmail)
+    }
+
+    @Test func emailWithDotsValid() {
+        #expect("first.last@example.com".isValidEmail)
+    }
+
+    @Test func noAtSignInvalid() {
+        #expect(!"userexample.com".isValidEmail)
+    }
+
+    @Test func noDomainInvalid() {
+        #expect(!"user@".isValidEmail)
+    }
+
+    @Test func noTLDInvalid() {
+        #expect(!"user@example".isValidEmail)
+    }
+
+    @Test func emptyStringInvalid() {
+        #expect(!"".isValidEmail)
+    }
+
+    @Test func numericLocalPartValid() {
+        #expect("123@example.com".isValidEmail)
+    }
+}
+
+// MARK: - isValidPhone Tests
+
+struct IsValidPhoneTests {
+
+    @Test func tenDigitsValid() {
+        #expect("5551234567".isValidPhone)
+    }
+
+    @Test func formattedUSPhoneValid() {
+        #expect("(555) 123-4567".isValidPhone)
+    }
+
+    @Test func internationalFormatValid() {
+        #expect("+1 555-123-4567".isValidPhone)
+    }
+
+    @Test func tooShortInvalid() {
+        #expect(!"12345".isValidPhone)
+    }
+
+    @Test func lettersInvalid() {
+        #expect(!"555-ABC-DEFG".isValidPhone)
+    }
+}
+
+// MARK: - Optional String Tests
+
+struct OptionalStringTests {
+
+    @Test func nilIsNilOrBlank() {
+        let s: String? = nil
+        #expect(s.isNilOrBlank)
+    }
+
+    @Test func emptyIsNilOrBlank() {
+        let s: String? = ""
+        #expect(s.isNilOrBlank)
+    }
+
+    @Test func whitespaceIsNilOrBlank() {
+        let s: String? = "   "
+        #expect(s.isNilOrBlank)
+    }
+
+    @Test func valueIsNotNilOrBlank() {
+        let s: String? = "hello"
+        #expect(!s.isNilOrBlank)
+    }
+
+    @Test func nilNilIfBlankReturnsNil() {
+        let s: String? = nil
+        #expect(s.nilIfBlank == nil)
+    }
+
+    @Test func blankOptionalNilIfBlankReturnsNil() {
+        let s: String? = "   "
+        #expect(s.nilIfBlank == nil)
+    }
+
+    @Test func valueOptionalNilIfBlankReturnsTrimmed() {
+        let s: String? = " hello "
+        #expect(s.nilIfBlank == "hello")
+    }
+}