refactor(user): simplify getE2Info/getUserInfo, fix the isp_asn miss bug

- getE2Info: collapse the obfuscated `if (cond) {} else { body }` chain into
  straight positive-form ifs; drop the redundant re-init of pair_line_info.
- getUserInfo: same de-obfuscation of the ISP block, and fix the same
  "Undefined array key isp_asn" bug already fixed in getStreamingUserInfo — the
  ISP-persist step ran even on a GeoIP miss (con_isp_name null), reading the
  undefined isp_asn key and writing a null isp_desc/as_number to the line.
- Extract the persist predicate both methods shared into a pure, tested
  UserRepository::ispChanged() helper (+ tests/Unit/UserRepositoryTest.php).

Verified: php -l, phpunit (423 tests, 944 assertions), make gates.

tests/Unit/UserRepositoryTest.php

@@ -0,0 +1,44 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+use XcVm\Domain\User\UserRepository;
+
+/**
+ * Unit tests for UserRepository::ispChanged() — the ISP-persist gate extracted
+ * from getStreamingUserInfo()/getUserInfo(). It guards the block that writes a
+ * looked-up ISP back to the line. A GeoIP lookup miss (empty con_isp_name) must
+ * NOT persist: the old code did, which read the undefined isp_asn key (the
+ * "Undefined array key isp_asn" warning) and stored a null isp_desc/as_number.
+ */
+final class UserRepositoryTest extends TestCase {
+
+	public function testPersistsWhenIspDetectedAndChanged(): void {
+		$this->assertTrue(UserRepository::ispChanged('Comcast', 0, 'Verizon'));
+	}
+
+	public function testFirstDetectionAgainstNullDescPersists(): void {
+		// No ISP stored yet -> a detected ISP counts as changed.
+		$this->assertTrue(UserRepository::ispChanged('Comcast', 0, null));
+	}
+
+	// ── the bug: a GeoIP miss must not reach the persist branch ──
+
+	public function testGeoipMissDoesNotPersist(): void {
+		$this->assertFalse(UserRepository::ispChanged(null, 0, 'Verizon'), 'null con_isp_name');
+		$this->assertFalse(UserRepository::ispChanged('', 0, 'Verizon'), 'empty con_isp_name');
+	}
+
+	// ── no write when nothing actually changed ──
+
+	public function testUnchangedIspDoesNotPersist(): void {
+		$this->assertFalse(UserRepository::ispChanged('Comcast', 0, 'Comcast'));
+		$this->assertFalse(UserRepository::ispChanged('Comcast', 0, 'comcast'), 'case-insensitive');
+		$this->assertFalse(UserRepository::ispChanged('COMCAST', 0, 'comcast'));
+	}
+
+	// ── a line already flagged in violation is left alone ──
+
+	public function testViolationDoesNotPersist(): void {
+		$this->assertFalse(UserRepository::ispChanged('Comcast', 1, 'Verizon'));
+	}
+}