chore: import upstream snapshot with attribution

TestsLinux/CodexBarLoggingPerformanceTests.swift

@@ -0,0 +1,82 @@
+import Logging
+import Testing
+@testable import CodexBarCore
+
+@Suite(.serialized)
+struct CodexBarLoggingPerformanceTests {
+    @Test
+    func `filtered log messages are not evaluated`() {
+        let probe = LogEvaluationProbe()
+        let logger = CodexBarLogger(minimumLevel: .info) { _, message, _ in
+            probe.loggedMessages.append(message)
+        }
+
+        logger.debug(probe.expensiveMessage())
+
+        #expect(probe.evaluations == 0)
+        #expect(probe.loggedMessages.isEmpty)
+
+        logger.info(probe.expensiveMessage())
+
+        #expect(probe.evaluations == 1)
+        #expect(probe.loggedMessages == ["evaluated"])
+    }
+
+    @Test
+    func `disabled file logging does not format metadata`() {
+        let sink = FileLogSink()
+        var handler = FileLogHandler(label: "test", sink: sink)
+        let probe = LogEvaluationProbe()
+        handler[metadataKey: "expensive"] = .stringConvertible(ExpensiveMetadataValue {
+            probe.evaluations += 1
+        })
+
+        handler.log(event: LogEvent(
+            level: .info,
+            message: "hello",
+            metadata: nil,
+            source: "test",
+            file: #filePath,
+            function: #function,
+            line: #line))
+
+        #expect(probe.evaluations == 0)
+    }
+
+    @Test
+    func `redactor leaves ordinary log lines unchanged`() {
+        let line = "CodexBar starting version=1.2.3 build=456"
+
+        #expect(LogRedactor.redact(line) == line)
+    }
+
+    @Test
+    func `redactor still redacts sensitive log lines`() {
+        let line = "Authorization: Bearer secret-token\nContact: user@example.com"
+        let redacted = LogRedactor.redact(line)
+
+        #expect(redacted.contains("secret-token") == false)
+        #expect(redacted.contains("user@example.com") == false)
+        #expect(redacted.contains("Authorization: <redacted>"))
+        #expect(redacted.contains("<redacted-email>"))
+    }
+}
+
+private final class LogEvaluationProbe: @unchecked Sendable {
+    var evaluations = 0
+    var loggedMessages: [String] = []
+
+    func expensiveMessage() -> String {
+        self.evaluations += 1
+        return "evaluated"
+    }
+}
+
+private struct ExpensiveMetadataValue: CustomStringConvertible, Sendable {
+    let onRender: @Sendable () -> Void
+
+    var description: String {
+        self.onRender()
+        return "rendered"
+    }
+}