Add FilenameDetector for path-based log type dispatch

New Detector that matches a configured regex against
LogFileInterface::getPath(). Returns a settable weight on match (default
0.95) and false otherwise, including when the log file has no known path
(StringLogFile, StreamLogFile). Lets game-specific Detectives prefer the
filename hint over content signatures when an upload's original name is
preserved.

test/tests/Detective/FilenameDetectorTest.php

@@ -0,0 +1,47 @@
+<?php
+
+namespace IndifferentKetchup\Codex\Test\Tests\Detective;
+
+use IndifferentKetchup\Codex\Detective\FilenameDetector;
+use IndifferentKetchup\Codex\Log\File\PathLogFile;
+use IndifferentKetchup\Codex\Log\File\StringLogFile;
+use PHPUnit\Framework\TestCase;
+
+class FilenameDetectorTest extends TestCase
+{
+    public function testReturnsWeightWhenPatternMatchesPath(): void
+    {
+        $detector = (new FilenameDetector())
+            ->setPattern('/simple\.log$/')
+            ->setWeight(0.9);
+        $detector->setLogFile(new PathLogFile(__DIR__ . "/../../data/simple.log"));
+
+        $this->assertSame(0.9, $detector->detect());
+    }
+
+    public function testReturnsFalseWhenPatternDoesNotMatch(): void
+    {
+        $detector = (new FilenameDetector())
+            ->setPattern('/notthere\.txt$/');
+        $detector->setLogFile(new PathLogFile(__DIR__ . "/../../data/simple.log"));
+
+        $this->assertFalse($detector->detect());
+    }
+
+    public function testReturnsFalseWhenLogFileHasNoPath(): void
+    {
+        $detector = (new FilenameDetector())
+            ->setPattern('/anything/');
+        $detector->setLogFile(new StringLogFile("content"));
+
+        $this->assertFalse($detector->detect());
+    }
+
+    public function testReturnsFalseWhenPatternUnset(): void
+    {
+        $detector = new FilenameDetector();
+        $detector->setLogFile(new PathLogFile(__DIR__ . "/../../data/simple.log"));
+
+        $this->assertFalse($detector->detect());
+    }
+}