Expose source path on LogFileInterface

Add LogFileInterface::getPath(): ?string so detectors can dispatch on a
filename hint when the original path is known. Default implementation on
the abstract LogFile base returns null; PathLogFile records its
constructor argument. StringLogFile and StreamLogFile inherit the null
default. Tests cover both the path and null-fallback cases.

src/Log/File/LogFile.php

@@ -10,6 +10,7 @@ namespace IndifferentKetchup\Codex\Log\File;
 abstract class LogFile implements LogFileInterface
 {
     protected ?string $content = null;
+    protected ?string $path = null;
 
     /**
      * Get the log file content
@@ -20,4 +21,14 @@ abstract class LogFile implements LogFileInterface
     {
         return $this->content;
     }
+
+    /**
+     * Get the source path of the log file when one is known
+     *
+     * @return string|null
+     */
+    public function getPath(): ?string
+    {
+        return $this->path;
+    }
 }