diff --git a/composer.json b/composer.json
index 3f664d8e243..81344995e6a 100644
--- a/composer.json
+++ b/composer.json
@@ -49,7 +49,7 @@
         "phpstan/phpstan-webmozart-assert": "^2.0",
         "phpunit/phpunit": "^13.3",
         "rector/jack": "^1.1",
-        "rector/swiss-knife": "^2.4.1",
+        "rector/swiss-knife": "^2.6",
         "shipmonk/composer-dependency-analyser": "^1.8",
         "symfony/process": "^8.1",
         "symplify/easy-coding-standard": "^13.2.13",
@@ -70,8 +70,7 @@
                 "src"
             ],
             "Rector\\Utils\\": "utils",
-            "Rector\\Utils\\PHPStan\\": "utils/phpstan/src",
-            "Rector\\Utils\\Duplicates\\": "utils/duplicates/src"
+            "Rector\\Utils\\PHPStan\\": "utils/phpstan/src"
         },
         "files": [
             "src/functions/node_helper.php"
@@ -84,7 +83,6 @@
                 "tests"
             ],
             "Rector\\Utils\\PHPStan\\Tests\\": "utils/phpstan/tests",
-            "Rector\\Utils\\Duplicates\\Tests\\": "utils/duplicates/tests",
             "E2e\\Parallel\\Reflection\\Resolver\\": "e2e/parallel-reflection-resolver/src/",
             "Rector\\Scripts\\": "scripts/src"
         },
@@ -106,12 +104,12 @@
             "@phpstan",
             "@test"
         ],
-        "test": "vendor/bin/fastunit tests rules-tests utils/phpstan/tests utils/duplicates/tests",
+        "test": "vendor/bin/fastunit tests rules-tests utils/phpstan/tests",
         "check-cs": "vendor/bin/ecs check --ansi",
         "fix-cs": "vendor/bin/ecs check --fix --ansi",
         "phpstan": "vendor/bin/phpstan analyse --ansi --memory-limit=512M",
         "rector": "bin/rector process --ansi",
-        "duplicated-code": "php utils/duplicates/bin/duplicates.php --min-lines 5 --min-tokens 150 src rules",
+        "duplicated-code": "vendor/bin/swiss-knife duplicated-code src rules --min-tokens 150 --min-lines 5",
         "preload": "php build/build-preload.php .",
         "release": "vendor/bin/rng --from-commit X --to-commit Y --remote-repository rectorphp/rector-symfony --remote-repository rectorphp/rector-doctrine --remote-repository rectorphp/rector-phpunit"
     },
diff --git a/rules-tests/TypeDeclaration/Rector/Property/TypedPropertyFromStrictConstructorRector/Fixture/skip_protected_property_redeclared_in_child.php.inc b/rules-tests/TypeDeclaration/Rector/Property/TypedPropertyFromStrictConstructorRector/Fixture/skip_protected_property_redeclared_in_child.php.inc
new file mode 100644
index 00000000000..626a225dba5
--- /dev/null
+++ b/rules-tests/TypeDeclaration/Rector/Property/TypedPropertyFromStrictConstructorRector/Fixture/skip_protected_property_redeclared_in_child.php.inc
@@ -0,0 +1,25 @@
+<?php
+
+namespace Rector\Tests\TypeDeclaration\Rector\Property\TypedPropertyFromStrictConstructorRector\Fixture;
+
+use Rector\Tests\TypeDeclaration\Rector\Property\TypedPropertyFromStrictConstructorRector\Source\SomeFrame;
+
+class ParentFrameReflower
+{
+    protected $frame;
+
+    public function __construct(SomeFrame $frame)
+    {
+        $this->frame = $frame;
+    }
+}
+
+class ChildFrameReflower extends ParentFrameReflower
+{
+    protected $frame;
+
+    public function __construct(SomeFrame $frame)
+    {
+        parent::__construct($frame);
+    }
+}
diff --git a/rules-tests/TypeDeclaration/Rector/Property/TypedPropertyFromStrictConstructorRector/Source/SomeFrame.php b/rules-tests/TypeDeclaration/Rector/Property/TypedPropertyFromStrictConstructorRector/Source/SomeFrame.php
new file mode 100644
index 00000000000..69c43893caa
--- /dev/null
+++ b/rules-tests/TypeDeclaration/Rector/Property/TypedPropertyFromStrictConstructorRector/Source/SomeFrame.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\TypeDeclaration\Rector\Property\TypedPropertyFromStrictConstructorRector\Source;
+
+final class SomeFrame
+{
+}
diff --git a/rules/TypeDeclaration/Guard/PropertyTypeOverrideGuard.php b/rules/TypeDeclaration/Guard/PropertyTypeOverrideGuard.php
index 46fc3ed9738..17deec5faeb 100644
--- a/rules/TypeDeclaration/Guard/PropertyTypeOverrideGuard.php
+++ b/rules/TypeDeclaration/Guard/PropertyTypeOverrideGuard.php
@@ -19,7 +19,10 @@ public function __construct(
 
     public function isLegal(Property $property, ClassReflection $classReflection): bool
     {
-        if (! $this->makePropertyTypedGuard->isLegal($property, $classReflection)) {
+        // protected property on a non-final class may be redeclared untyped in a child class,
+        // which would cause a covariance fatal error once only the parent is typed
+        $inlinePublic = ! $property->isProtected();
+        if (! $this->makePropertyTypedGuard->isLegal($property, $classReflection, $inlinePublic)) {
             return false;
         }
 
diff --git a/utils/duplicates/README.md b/utils/duplicates/README.md
deleted file mode 100644
index 0950b62da83..00000000000
--- a/utils/duplicates/README.md
+++ /dev/null
@@ -1,19 +0,0 @@
-# Duplicates
-
-Token-based copy-paste detector, a small clone of [phpcpd](https://github.com/phpcpd-next/phpcpd).
-
-It tokenizes PHP with `token_get_all()`, strips whitespace and comments, then finds exact duplicate token spans with a Rabin-Karp rolling hash.
-
-## Usage
-
-```bash
-php utils/duplicates/bin/duplicates.php src rules
-```
-
-Options:
-
-- `--min-lines` minimum lines of a clone (default `5`)
-- `--min-tokens` minimum tokens of a clone (default `70`)
-- `--fuzzy` ignore variable names when matching
-
-Exit code is `1` when clones are found, `0` otherwise.
diff --git a/utils/duplicates/bin/duplicates.php b/utils/duplicates/bin/duplicates.php
deleted file mode 100644
index fa06fd252f9..00000000000
--- a/utils/duplicates/bin/duplicates.php
+++ /dev/null
@@ -1,109 +0,0 @@
-#!/usr/bin/env php
-<?php
-
-declare(strict_types=1);
-
-use Rector\Utils\Duplicates\CloneDetector;
-use Symfony\Component\Finder\Finder;
-
-$autoloadFile = __DIR__ . '/../../../vendor/autoload.php';
-if (! file_exists($autoloadFile)) {
-    fwrite(STDERR, 'Composer autoload not found, run "composer install" first.' . PHP_EOL);
-    exit(1);
-}
-
-require_once $autoloadFile;
-
-$minLines = 5;
-$minTokens = 70;
-$fuzzy = false;
-$paths = [];
-
-$args = array_slice($argv, 1);
-for ($i = 0; $i < count($args); ++$i) {
-    $arg = $args[$i];
-
-    if ($arg === '--fuzzy') {
-        $fuzzy = true;
-    } elseif ($arg === '--min-lines') {
-        $minLines = (int) ($args[++$i] ?? $minLines);
-    } elseif ($arg === '--min-tokens') {
-        $minTokens = (int) ($args[++$i] ?? $minTokens);
-    } else {
-        $paths[] = $arg;
-    }
-}
-
-if ($paths === []) {
-    fwrite(STDERR, 'Usage: php bin/duplicates.php [--min-lines N] [--min-tokens N] [--fuzzy] <path>...' . PHP_EOL);
-    exit(1);
-}
-
-$filePaths = [];
-foreach ($paths as $path) {
-    if (is_file($path)) {
-        $filePaths[] = $path;
-        continue;
-    }
-
-    if (! is_dir($path)) {
-        continue;
-    }
-
-    $finder = new Finder()
-        ->files()
-        ->in($path)
-        ->name('*.php');
-
-    foreach ($finder as $fileInfo) {
-        $realPath = $fileInfo->getRealPath();
-        if ($realPath === false) {
-            continue;
-        }
-
-        $filePaths[] = $realPath;
-    }
-}
-
-if ($filePaths === []) {
-    echo 'No PHP files found in the given paths.' . PHP_EOL;
-    exit(0);
-}
-
-$cloneDetector = new CloneDetector($minLines, $minTokens, $fuzzy);
-$clones = $cloneDetector->detect($filePaths);
-
-if ($clones === []) {
-    echo sprintf('[OK] No duplicates found in %d files', count($filePaths)) . PHP_EOL;
-    exit(0);
-}
-
-$duplicatedLines = 0;
-foreach ($clones as $clone) {
-    echo sprintf(
-        '  - %s:%d-%d (%d lines, %d tokens)',
-        $clone->firstFile->filePath,
-        $clone->firstFile->startLine,
-        $clone->firstFile->endLine,
-        $clone->lines,
-        $clone->tokens
-    ) . PHP_EOL;
-    echo sprintf(
-        '    %s:%d-%d',
-        $clone->secondFile->filePath,
-        $clone->secondFile->startLine,
-        $clone->secondFile->endLine
-    ) . PHP_EOL;
-    echo PHP_EOL;
-
-    $duplicatedLines += $clone->lines;
-}
-
-fwrite(STDERR, sprintf(
-    '[ERROR] Found %d clones with %d duplicated lines in %d scanned files',
-    count($clones),
-    $duplicatedLines,
-    count($filePaths)
-) . PHP_EOL);
-
-exit(1);
diff --git a/utils/duplicates/src/CloneDetector.php b/utils/duplicates/src/CloneDetector.php
deleted file mode 100644
index 62629984989..00000000000
--- a/utils/duplicates/src/CloneDetector.php
+++ /dev/null
@@ -1,196 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Rector\Utils\Duplicates;
-
-use Rector\Utils\Duplicates\ValueObject\CodeClone;
-use Rector\Utils\Duplicates\ValueObject\CodeCloneFile;
-
-/**
- * Token-based copy-paste detector using a Rabin-Karp rolling hash over the
- * normalized token stream, mirroring the classic phpcpd behaviour.
- * @see \Rector\Utils\Duplicates\Tests\CloneDetectorTest
- */
-final class CloneDetector
-{
-    /**
-     * Tokens that carry no structural meaning for clone detection.
-     *
-     * @var array<int, true>
-     */
-    private const array IGNORED_TOKENS = [
-        T_INLINE_HTML => true,
-        T_COMMENT => true,
-        T_DOC_COMMENT => true,
-        T_OPEN_TAG => true,
-        T_OPEN_TAG_WITH_ECHO => true,
-        T_CLOSE_TAG => true,
-        T_WHITESPACE => true,
-    ];
-
-    /**
-     * Bytes contributed by each kept token to the signature: 1 type byte + 4 CRC32 bytes.
-     */
-    private const int BYTES_PER_TOKEN = 5;
-
-    /**
-     * First seen location per window hash: hash => [filePath, tokenIndex].
-     *
-     * @var array<string, array{string, int}>
-     */
-    private array $hashes = [];
-
-    /**
-     * Per-file token line numbers, kept for span line lookup.
-     *
-     * @var array<string, int[]>
-     */
-    private array $fileLines = [];
-
-    /**
-     * @var CodeClone[]
-     */
-    private array $clones = [];
-
-    public function __construct(
-        private readonly int $minLines,
-        private readonly int $minTokens,
-        private readonly bool $fuzzy
-    ) {
-    }
-
-    /**
-     * @param string[] $filePaths
-     * @return CodeClone[]
-     */
-    public function detect(array $filePaths): array
-    {
-        foreach ($filePaths as $filePath) {
-            $this->processFile($filePath);
-        }
-
-        return $this->clones;
-    }
-
-    private function processFile(string $filePath): void
-    {
-        $source = file_get_contents($filePath);
-        if ($source === false) {
-            return;
-        }
-
-        [$signature, $lines] = $this->tokenize($source);
-        $this->fileLines[$filePath] = $lines;
-
-        $tokenCount = count($lines);
-        if ($tokenCount < $this->minTokens) {
-            return;
-        }
-
-        $lastWindow = $tokenCount - $this->minTokens;
-        $windowBytes = $this->minTokens * self::BYTES_PER_TOKEN;
-
-        $found = false;
-        $firstToken = 0;
-        $originFile = '';
-        $originToken = 0;
-
-        for ($i = 0; $i <= $lastWindow; ++$i) {
-            $hash = substr(md5(substr($signature, $i * self::BYTES_PER_TOKEN, $windowBytes), true), 0, 8);
-
-            if (isset($this->hashes[$hash])) {
-                if (! $found) {
-                    $found = true;
-                    $firstToken = $i;
-                    [$originFile, $originToken] = $this->hashes[$hash];
-                }
-
-                continue;
-            }
-
-            if ($found) {
-                $this->recordClone($originFile, $originToken, $filePath, $firstToken, $i);
-                $found = false;
-            }
-
-            $this->hashes[$hash] = [$filePath, $i];
-        }
-
-        if ($found) {
-            $this->recordClone($originFile, $originToken, $filePath, $firstToken, $lastWindow + 1);
-        }
-    }
-
-    private function recordClone(
-        string $originFile,
-        int $originToken,
-        string $currentFile,
-        int $currentToken,
-        int $mismatchWindow
-    ): void {
-        $windowCount = $mismatchWindow - $currentToken;
-        $tokenSpan = $windowCount + $this->minTokens - 1;
-
-        $originLines = $this->fileLines[$originFile];
-        $currentLines = $this->fileLines[$currentFile];
-
-        $originStartLine = $originLines[$originToken];
-        $originEndLine = $originLines[min($originToken + $tokenSpan - 1, count($originLines) - 1)];
-
-        $currentStartLine = $currentLines[$currentToken];
-        $currentEndLine = $currentLines[min($currentToken + $tokenSpan - 1, count($currentLines) - 1)];
-
-        $numberOfLines = $originEndLine - $originStartLine + 1;
-        if ($numberOfLines < $this->minLines) {
-            return;
-        }
-
-        $this->clones[] = new CodeClone(
-            new CodeCloneFile($originFile, $originStartLine, $originEndLine),
-            new CodeCloneFile($currentFile, $currentStartLine, $currentEndLine),
-            $numberOfLines,
-            $tokenSpan
-        );
-    }
-
-    /**
-     * Builds the token signature and the parallel line map for a source string.
-     *
-     * @return array{string, int[]}
-     */
-    private function tokenize(string $source): array
-    {
-        $signature = '';
-        $lines = [];
-        $currentLine = 1;
-
-        foreach (token_get_all($source) as $token) {
-            if (is_array($token)) {
-                $tokenId = $token[0];
-                $tokenText = $token[1];
-                $currentLine = $token[2];
-
-                if (isset(self::IGNORED_TOKENS[$tokenId])) {
-                    $currentLine += substr_count($tokenText, "\n");
-                    continue;
-                }
-
-                if ($this->fuzzy && $tokenId === T_VARIABLE) {
-                    $tokenText = '$';
-                }
-
-                $signature .= chr($tokenId & 255) . pack('N*', crc32($tokenText));
-                $lines[] = $currentLine;
-                $currentLine += substr_count($tokenText, "\n");
-
-                continue;
-            }
-
-            $signature .= chr(0) . pack('N*', crc32($token));
-            $lines[] = $currentLine;
-        }
-
-        return [$signature, $lines];
-    }
-}
diff --git a/utils/duplicates/src/ValueObject/CodeClone.php b/utils/duplicates/src/ValueObject/CodeClone.php
deleted file mode 100644
index ea89ea758ef..00000000000
--- a/utils/duplicates/src/ValueObject/CodeClone.php
+++ /dev/null
@@ -1,16 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Rector\Utils\Duplicates\ValueObject;
-
-final readonly class CodeClone
-{
-    public function __construct(
-        public CodeCloneFile $firstFile,
-        public CodeCloneFile $secondFile,
-        public int $lines,
-        public int $tokens
-    ) {
-    }
-}
diff --git a/utils/duplicates/src/ValueObject/CodeCloneFile.php b/utils/duplicates/src/ValueObject/CodeCloneFile.php
deleted file mode 100644
index cbf24bdeb59..00000000000
--- a/utils/duplicates/src/ValueObject/CodeCloneFile.php
+++ /dev/null
@@ -1,15 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Rector\Utils\Duplicates\ValueObject;
-
-final readonly class CodeCloneFile
-{
-    public function __construct(
-        public string $filePath,
-        public int $startLine,
-        public int $endLine
-    ) {
-    }
-}
diff --git a/utils/duplicates/tests/CloneDetectorTest.php b/utils/duplicates/tests/CloneDetectorTest.php
deleted file mode 100644
index 849314c32dc..00000000000
--- a/utils/duplicates/tests/CloneDetectorTest.php
+++ /dev/null
@@ -1,40 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Rector\Utils\Duplicates\Tests;
-
-use PHPUnit\Framework\TestCase;
-use Rector\Utils\Duplicates\CloneDetector;
-
-final class CloneDetectorTest extends TestCase
-{
-    public function testDetectsDuplicateAcrossFiles(): void
-    {
-        $cloneDetector = new CloneDetector(3, 25, false);
-
-        $clones = $cloneDetector->detect([
-            __DIR__ . '/Fixture/first_duplicate.php.inc',
-            __DIR__ . '/Fixture/second_duplicate.php.inc',
-        ]);
-
-        $this->assertCount(1, $clones);
-
-        $codeClone = $clones[0];
-        $this->assertStringEndsWith('first_duplicate.php.inc', $codeClone->firstFile->filePath);
-        $this->assertStringEndsWith('second_duplicate.php.inc', $codeClone->secondFile->filePath);
-        $this->assertGreaterThanOrEqual(3, $codeClone->lines);
-    }
-
-    public function testDoesNotReportUniqueCode(): void
-    {
-        $cloneDetector = new CloneDetector(3, 25, false);
-
-        $clones = $cloneDetector->detect([
-            __DIR__ . '/Fixture/first_duplicate.php.inc',
-            __DIR__ . '/Fixture/unique.php.inc',
-        ]);
-
-        $this->assertSame([], $clones);
-    }
-}
diff --git a/utils/duplicates/tests/Fixture/first_duplicate.php.inc b/utils/duplicates/tests/Fixture/first_duplicate.php.inc
deleted file mode 100644
index dded1cbdc0d..00000000000
--- a/utils/duplicates/tests/Fixture/first_duplicate.php.inc
+++ /dev/null
@@ -1,13 +0,0 @@
-<?php
-
-function firstDuplicate(): int
-{
-    $total = 0;
-    $items = [1, 2, 3, 4, 5];
-
-    foreach ($items as $item) {
-        $total += $item * 2;
-    }
-
-    return $total;
-}
diff --git a/utils/duplicates/tests/Fixture/second_duplicate.php.inc b/utils/duplicates/tests/Fixture/second_duplicate.php.inc
deleted file mode 100644
index dded1cbdc0d..00000000000
--- a/utils/duplicates/tests/Fixture/second_duplicate.php.inc
+++ /dev/null
@@ -1,13 +0,0 @@
-<?php
-
-function firstDuplicate(): int
-{
-    $total = 0;
-    $items = [1, 2, 3, 4, 5];
-
-    foreach ($items as $item) {
-        $total += $item * 2;
-    }
-
-    return $total;
-}
diff --git a/utils/duplicates/tests/Fixture/unique.php.inc b/utils/duplicates/tests/Fixture/unique.php.inc
deleted file mode 100644
index be01c634fe9..00000000000
--- a/utils/duplicates/tests/Fixture/unique.php.inc
+++ /dev/null
@@ -1,12 +0,0 @@
-<?php
-
-function uniqueLogic(string $name): string
-{
-    $greeting = 'Hello ' . $name;
-
-    if ($name === '') {
-        return 'Hello stranger';
-    }
-
-    return strtoupper($greeting);
-}