chore: import upstream snapshot with attribution

Tests/CodexBarTests/LoadingPatternTests.swift

@@ -0,0 +1,34 @@
+import Foundation
+import Testing
+@testable import CodexBar
+
+struct LoadingPatternTests {
+    @Test
+    func `values stay within bounds`() {
+        for pattern in LoadingPattern.allCases {
+            for phase in stride(from: 0.0, through: Double.pi * 2, by: Double.pi / 6) {
+                let v = pattern.value(phase: phase)
+                #expect(v >= 0 && v <= 100, "pattern \(pattern) out of bounds at phase \(phase)")
+            }
+        }
+    }
+
+    @Test
+    func `knight rider ping pongs`() {
+        let pattern = LoadingPattern.knightRider
+        let mid = pattern.value(phase: 0) // sin 0 = 0 => 50
+        let min = pattern.value(phase: -Double.pi / 2) // sin -pi/2 = -1 => 0
+        let max = pattern.value(phase: Double.pi / 2) // sin pi/2 = 1 => 100
+        #expect(min <= mid && mid <= max)
+        #expect(min == 0)
+        #expect(max == 100)
+    }
+
+    @Test
+    func `secondary offset differs`() {
+        let pattern = LoadingPattern.cylon
+        let primary = pattern.value(phase: 0)
+        let secondary = pattern.value(phase: pattern.secondaryOffset)
+        #expect(primary != secondary, "secondary should be offset from primary")
+    }
+}