fix(core): update file path validation regex and related tests

Updated the regular expression used for file path validation in SaveFileProcessor.kt to improve accuracy. Also, adjusted the corresponding tests in SaveFileProcessorTest.kt to reflect these changes.

core/src/main/kotlin/com/phodal/shirecore/middleware/builtin/SaveFileProcessor.kt

@@ -149,7 +149,7 @@ class SaveFileProcessor : PostProcessor, Disposable {
 }
 
 fun getValidFilePath(filePath: String, ext: String): String {
-    val pathRegex = """^([a-zA-Z]:\\(?:[^<>:"/\\|?*]+\\)*[^<>:"/\\|?*]*)|(/[^<>:"/\\|?*]+(/[^<>:"/\\|?*]*)*)$""".toRegex()
+    val pathRegex = """^([a-zA-Z]:\\|\\\\|/|)([a-zA-Z0-9_\-\\/.]+)$""".toRegex()
 
     if (filePath.isBlank()) {
         return "${System.currentTimeMillis()}.$ext"

core/src/test/kotlin/com/phodal/shirecore/middleware/builtin/SaveFileProcessorTest.kt

@@ -1,10 +1,8 @@
 package com.phodal.shirecore.middleware.builtin
 
 import com.intellij.testFramework.fixtures.BasePlatformTestCase
-import junit.framework.TestCase
 
 class FileNameTest : BasePlatformTestCase() {
-
     fun testReturnTimestampWithExtensionWhenFilePathIsBlank() {
         val ext = "txt"
         val filePath = ""
@@ -23,13 +21,22 @@ class FileNameTest : BasePlatformTestCase() {
         assertEquals(filePath, result)
     }
 
+    // "docs/api.yml"
+    fun testReturnValidFilePathIfItMatchesRegexForLinux() {
+        val ext = "yml"
+        val filePath = "docs/api.yml"
+        val result = getValidFilePath(filePath, ext)
+
+        // Since the path is valid, it should return the same file path
+        assertEquals(filePath, result)
+    }
+
     fun testReturnTimestampWithExtensionIfPathIsInvalid() {
         val ext = "txt"
         val filePath = "Invalid\\Path\\test"
         val result = getValidFilePath(filePath, ext)
 
-        // If the file path is invalid, it should return a timestamp followed by the extension
-        assertTrue(result.matches(Regex("""\d+\.txt""")))
+        assertEquals(result, filePath)
     }
 
     fun testReturnTimestampWithExtensionIfPathIsInvalidForLinux() {