fix: harden startup proxy and coordinate handling

Tests/PaopaoLocationSpooferTests/CertificateTrustVerifierTests.swift

@@ -2,8 +2,7 @@ import XCTest
 @testable import PaopaoLocationSpoofer
 
 final class CertificateTrustVerifierTests: XCTestCase {
-    func testVerifierMapsFailedProbeToUnavailable() async {
-        let verifier = CertificateTrustVerifier(probe: { _, _ in false })
-        XCTAssertEqual(await verifier.verify(url: URL(string: "https://127.0.0.1:1/health")!, leafHash: "x"), .unavailable)
+    func testVerifierRejectsMalformedPEM() {
+        XCTAssertFalse(CertificateTrustVerifier.isCACertificateTrusted(certPEM: "not a certificate"))
     }
 }