revert: remove unnecessary ReDoS validation and array copying

- Remove ReDoS validation: user-provided regex patterns are trusted
  (core config values, user's responsibility)
- Revert array copying in sortedImports: matches old TypeScript Hero
  behavior (groups are reset between calls anyway)
- Add docstring noting regex patterns are trusted without validation

The agents gave false warnings about these being bugs.

Author: JohannesHoppe

src/imports/import-grouping/keyword-import-group.ts

@@ -11,8 +11,7 @@ export class KeywordImportGroup implements ImportGroup {
   public readonly imports: Import[] = [];
 
   public get sortedImports(): Import[] {
-    // IMPORTANT: Copy array before sorting to avoid mutating the original
-    return [...this.imports].sort((i1, i2) => importSort(i1, i2, this.order));
+    return this.imports.sort((i1, i2) => importSort(i1, i2, this.order));
   }
 
   constructor(

src/imports/import-grouping/regex-import-group.ts

@@ -3,27 +3,18 @@ import { importSort } from '../import-utilities';
 import { ImportGroup } from './import-group';
 import { ImportGroupOrder } from './import-group-order';
 
-/**
- * Detects potentially dangerous regex patterns that could cause catastrophic backtracking (ReDoS).
- * Checks for nested quantifiers like (a+)+, (a*)+, etc.
- */
-function isPotentiallyDangerousRegex(pattern: string): boolean {
-  // Detect nested quantifiers: (pattern)+ or (pattern)* where pattern contains + or *
-  // This is a simple heuristic, not comprehensive
-  const nestedQuantifierPattern = /\([^)]*[+*][^)]*\)[+*]/;
-  return nestedQuantifierPattern.test(pattern);
-}
-
 /**
  * Import group that processes all imports that match a certain regex (the lib name).
+ *
+ * NOTE: User-provided regex patterns are trusted without validation.
+ * This is a core configuration value - users are responsible for providing valid patterns.
  */
 export class RegexImportGroup implements ImportGroup {
   public readonly imports: Import[] = [];
   private readonly compiledRegex: RegExp;
 
   public get sortedImports(): Import[] {
-    // IMPORTANT: Copy array before sorting to avoid mutating the original
-    const sorted = [...this.imports].sort((i1, i2) =>
+    const sorted = this.imports.sort((i1, i2) =>
       importSort(i1, i2, this.order),
     );
     return [
@@ -51,23 +42,7 @@ export class RegexImportGroup implements ImportGroup {
     regexString = regexString.endsWith('/')
       ? regexString.substring(0, regexString.length - 1)
       : regexString;
-
-    // Check for potentially dangerous regex patterns (ReDoS protection)
-    // Note: We just log to debug console, which is visible in Extension Development Host
-    if (isPotentiallyDangerousRegex(regexString)) {
-      // eslint-disable-next-line no-console
-      console.warn(`[RegexImportGroup] Warning: Potentially dangerous regex pattern detected: ${this.regex}`);
-    }
-
-    // Try to compile regex, use fallback if invalid
-    try {
-      this.compiledRegex = new RegExp(regexString);
-    } catch {
-      // Invalid regex - use a pattern that never matches
-      // eslint-disable-next-line no-console
-      console.error(`[RegexImportGroup] Invalid regex pattern: ${this.regex}`);
-      this.compiledRegex = /(?!)/; // Never matches
-    }
+    this.compiledRegex = new RegExp(regexString);
   }
 
   public reset(): void {

src/imports/import-grouping/remain-import-group.ts

@@ -10,8 +10,7 @@ export class RemainImportGroup implements ImportGroup {
   public readonly imports: Import[] = [];
 
   public get sortedImports(): Import[] {
-    // IMPORTANT: Copy array before sorting to avoid mutating the original
-    const sorted = [...this.imports].sort((i1, i2) =>
+    const sorted = this.imports.sort((i1, i2) =>
       importSort(i1, i2, this.order),
     );
     return [