diff --git a/phpstan.neon b/phpstan.neon
index 8fc3894..0ec59d3 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -2,6 +2,6 @@ includes:
     - phar://phpstan.phar/conf/bleedingEdge.neon
 
 parameters:
-    level: 8
+    level: 9
     paths:
         - src
diff --git a/src/Block/Inspector.php b/src/Block/Inspector.php
index eaea02a..aa4d20a 100644
--- a/src/Block/Inspector.php
+++ b/src/Block/Inspector.php
@@ -89,7 +89,8 @@ public function getJsUrl(): string
      */
     public function getTheme(): string
     {
-        return (string) $this->scopeConfig->getValue('mageforge/inspector/theme') ?: 'dark';
+        $value = $this->scopeConfig->getValue('mageforge/inspector/theme');
+        return is_string($value) && $value !== '' ? $value : 'dark';
     }
 
     /**
diff --git a/src/Console/Command/AbstractCommand.php b/src/Console/Command/AbstractCommand.php
index 561402d..e7bb887 100644
--- a/src/Console/Command/AbstractCommand.php
+++ b/src/Console/Command/AbstractCommand.php
@@ -6,8 +6,8 @@
 
 use Laravel\Prompts\SelectPrompt;
 use Magento\Framework\Console\Cli;
-use OpenForgeProject\MageForge\Service\ThemeSuggester;
 use OpenForgeProject\MageForge\Model\ThemeList;
+use OpenForgeProject\MageForge\Service\ThemeSuggester;
 use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
@@ -183,7 +183,7 @@ protected function handleInvalidThemeWithSuggestions(
                 return null;
             }
 
-            return $selection;
+            return is_string($selection) ? $selection : null;
         } catch (\Exception $e) {
             $this->resetPromptEnvironment();
             $this->io->error('Selection failed: ' . $e->getMessage());
@@ -487,10 +487,8 @@ private function removeSecureEnvironmentValue(string $name): void
      * @param ThemeList $themeList
      * @return array<string>
      */
-    protected function resolveVendorThemes(
-        array $themeCodes,
-        ThemeList $themeList
-    ): array {
+    protected function resolveVendorThemes(array $themeCodes, ThemeList $themeList): array
+    {
         $resolved = [];
         $availableThemes = null;
 
@@ -502,10 +500,7 @@ protected function resolveVendorThemes(
             if ($isExplicitWildcard || $isVendorOnly) {
                 // Lazy-load themes only when needed
                 if ($availableThemes === null) {
-                    $availableThemes = array_map(
-                        fn($theme) => $theme->getCode(),
-                        $themeList->getAllThemes()
-                    );
+                    $availableThemes = array_map(fn($theme) => $theme->getCode(), $themeList->getAllThemes());
                 }
 
                 if ($isExplicitWildcard) {
@@ -514,10 +509,10 @@ protected function resolveVendorThemes(
                     $prefix = $code . '/'; // e.g. "Vendor" -> "Vendor/"
                 }
 
-                $matched = array_filter(
-                    $availableThemes,
-                    fn(string $availableCode) => \str_starts_with($availableCode, $prefix)
-                );
+                $matched = array_filter($availableThemes, fn(string $availableCode) => \str_starts_with(
+                    $availableCode,
+                    $prefix,
+                ));
 
                 if (empty($matched)) {
                     $this->io->warning(sprintf("No themes found for vendor/prefix '%s'", $prefix));
@@ -532,7 +527,7 @@ protected function resolveVendorThemes(
                         "Resolved vendor '%s' to %d theme(s): %s",
                         $code,
                         count($matched),
-                        implode(', ', $matched)
+                        implode(', ', $matched),
                     ));
 
                     foreach ($matched as $match) {
diff --git a/src/Console/Command/Dev/InspectorCommand.php b/src/Console/Command/Dev/InspectorCommand.php
index 7719e75..5ba4523 100644
--- a/src/Console/Command/Dev/InspectorCommand.php
+++ b/src/Console/Command/Dev/InspectorCommand.php
@@ -82,7 +82,8 @@ protected function configure(): void
      */
     protected function executeCommand(InputInterface $input, OutputInterface $output): int
     {
-        $action = strtolower((string) $input->getArgument(self::ARGUMENT_ACTION));
+        $arg = $input->getArgument(self::ARGUMENT_ACTION);
+        $action = strtolower(is_string($arg) ? $arg : '');
 
         // Validate action
         if (!in_array($action, ['enable', 'disable', 'status'], true)) {
diff --git a/src/Console/Command/Hyva/CompatibilityCheckCommand.php b/src/Console/Command/Hyva/CompatibilityCheckCommand.php
index 4265c98..4cd297e 100644
--- a/src/Console/Command/Hyva/CompatibilityCheckCommand.php
+++ b/src/Console/Command/Hyva/CompatibilityCheckCommand.php
@@ -19,6 +19,10 @@
  *
  * Scans modules for RequireJS, Knockout.js, jQuery, and UI Components usage
  * that would be incompatible with Hyvä themes.
+ *
+ * @phpstan-import-type CheckResults from \OpenForgeProject\MageForge\Service\Hyva\CompatibilityChecker
+ * @phpstan-import-type CheckSummary from \OpenForgeProject\MageForge\Service\Hyva\CompatibilityChecker
+ * @phpstan-import-type ModuleEntry from \OpenForgeProject\MageForge\Service\Hyva\CompatibilityChecker
  */
 class CompatibilityCheckCommand extends AbstractCommand
 {
@@ -146,7 +150,7 @@ private function runInteractiveMode(InputInterface $input, OutputInterface $outp
             // Detailed view confirmation
             $detailedPrompt = new ConfirmPrompt(label: 'Show detailed file-level issues?', default: false);
 
-            $detailed = $detailedPrompt->prompt();
+            $detailed = (bool) $detailedPrompt->prompt();
 
             // Map selected options to flags
             $showAll = $displayMode === self::DISPLAY_MODE_SHOW_ALL;
@@ -193,10 +197,10 @@ private function runInteractiveMode(InputInterface $input, OutputInterface $outp
      */
     private function runDirectMode(InputInterface $input, OutputInterface $output): int
     {
-        $showAll = $input->getOption(self::OPTION_SHOW_ALL);
-        $thirdPartyOnly = $input->getOption(self::OPTION_THIRD_PARTY_ONLY);
-        $includeVendor = $input->getOption(self::OPTION_INCLUDE_VENDOR);
-        $detailed = $input->getOption(self::OPTION_DETAILED);
+        $showAll = (bool) $input->getOption(self::OPTION_SHOW_ALL);
+        $thirdPartyOnly = (bool) $input->getOption(self::OPTION_THIRD_PARTY_ONLY);
+        $includeVendor = (bool) $input->getOption(self::OPTION_INCLUDE_VENDOR);
+        $detailed = (bool) $input->getOption(self::OPTION_DETAILED);
 
         $this->io->title('Hyvä Theme Compatibility Check');
 
@@ -271,7 +275,7 @@ private function runScan(
      * Display compatibility check results
      *
      * @param array $results
-     * @phpstan-param array<string, mixed> $results
+     * @phpstan-param CheckResults $results
      * @param bool $showAll
      */
     private function displayResults(array $results, bool $showAll): void
@@ -292,7 +296,7 @@ private function displayResults(array $results, bool $showAll): void
      * Display detailed file-level issues
      *
      * @param array $results
-     * @phpstan-param array<string, mixed> $results
+     * @phpstan-param CheckResults $results
      */
     private function displayDetailedIssues(array $results): void
     {
@@ -333,7 +337,7 @@ private function displayDetailedIssues(array $results): void
      * Display summary statistics
      *
      * @param array $results
-     * @phpstan-param array<string, mixed> $results
+     * @phpstan-param array{summary: CheckSummary} $results
      */
     private function displaySummary(array $results): void
     {
diff --git a/src/Console/Command/System/CheckCommand.php b/src/Console/Command/System/CheckCommand.php
index d8ec8f7..774ec50 100644
--- a/src/Console/Command/System/CheckCommand.php
+++ b/src/Console/Command/System/CheckCommand.php
@@ -162,8 +162,13 @@ private function getLatestLtsNodeVersion(): string
                 return 'Unknown';
             }
 
+            /** @var array<int, array<string, mixed>> $nodes */
             foreach ($nodes as $node) {
-                if (isset($node['lts']) && $node['lts'] !== false) {
+                if (isset($node['lts'])
+                    && $node['lts'] !== false
+                    && isset($node['version'])
+                    && is_string($node['version'])
+                ) {
                     return trim($node['version'], 'v');
                 }
             }
@@ -407,12 +412,15 @@ private function getSearchEngineFromMagentoConfig(): ?string
     private function checkSearchEngineViaDeploymentConfig($objectManager): ?string
     {
         try {
+            /** @var \Magento\Framework\App\DeploymentConfig $deploymentConfig */
             $deploymentConfig = $objectManager->get(\Magento\Framework\App\DeploymentConfig::class);
             $engineConfig = $deploymentConfig->get('system/search/engine');
 
-            if (!empty($engineConfig)) {
-                $host = $deploymentConfig->get('system/search/engine_host') ?: 'localhost';
-                $port = $deploymentConfig->get('system/search/engine_port') ?: '9200';
+            if (!empty($engineConfig) && is_string($engineConfig)) {
+                $hostRaw = $deploymentConfig->get('system/search/engine_host');
+                $portRaw = $deploymentConfig->get('system/search/engine_port');
+                $host = is_string($hostRaw) ? $hostRaw : 'localhost';
+                $port = is_string($portRaw) ? $portRaw : '9200';
 
                 $url = "http://{$host}:{$port}";
                 if ($this->testElasticsearchConnection($url)) {
@@ -439,12 +447,11 @@ private function checkSearchEngineViaDeploymentConfig($objectManager): ?string
     private function checkSearchEngineViaEngineResolver($objectManager): ?string
     {
         try {
+            /** @var \Magento\Framework\Search\EngineResolverInterface $engineResolver */
             $engineResolver = $objectManager->get(\Magento\Framework\Search\EngineResolverInterface::class);
-            if ($engineResolver) {
-                $currentEngine = $engineResolver->getCurrentSearchEngine();
-                if (!empty($currentEngine)) {
-                    return ucfirst($currentEngine) . ' (Magento config)';
-                }
+            $currentEngine = $engineResolver->getCurrentSearchEngine();
+            if (!empty($currentEngine)) {
+                return ucfirst($currentEngine) . ' (Magento config)';
             }
         } catch (\Exception $e) {
             if ($this->io->isVerbose()) {
@@ -541,12 +548,16 @@ private function getSearchEngineHosts(): array
      */
     private function formatSearchEngineVersion(array $info): string
     {
-        if (isset($info['version']['distribution']) && $info['version']['distribution'] === 'opensearch') {
-            return 'OpenSearch ' . $info['version']['number'];
+        $version = $info['version'] ?? null;
+        if (!is_array($version)) {
+            return 'Search Engine Available';
+        }
+        if (isset($version['distribution']) && $version['distribution'] === 'opensearch') {
+            return 'OpenSearch ' . (is_string($version['number']) ? $version['number'] : '');
         }
 
-        if (isset($info['version']['number'])) {
-            return 'Elasticsearch ' . $info['version']['number'];
+        if (isset($version['number'])) {
+            return 'Elasticsearch ' . (is_string($version['number']) ? $version['number'] : '');
         }
 
         return 'Search Engine Available';
@@ -597,6 +608,7 @@ private function tryMagentoHttpClient(string $url): ?array
             if ($status === 200 && !empty($response)) {
                 $data = json_decode($response, true);
                 if (is_array($data)) {
+                    /** @var array<string, mixed> $data */
                     return $data;
                 }
             }
@@ -661,10 +673,24 @@ private function getDiskSpace(): string
         $totalSpace = disk_total_space('.');
         $freeSpace = disk_free_space('.');
 
-        $totalGB = round((($totalSpace / 1024) / 1024) / 1024, 2);
-        $freeGB = round((($freeSpace / 1024) / 1024) / 1024, 2);
+        if ($totalSpace === false || $freeSpace === false) {
+            return 'Unknown';
+        }
+
+        if ($totalSpace <= 0) {
+            $totalGB = 0.0;
+            $usedGB = 0.0;
+            $usedPercent = 0.0;
+
+            return "$usedGB GB / $totalGB GB ($usedPercent%)";
+        }
+
+        $totalGB = round($totalSpace / 1024 / 1024 / 1024, 2);
+        $freeGB = round($freeSpace / 1024 / 1024 / 1024, 2);
         $usedGB = round($totalGB - $freeGB, 2);
-        $usedPercent = round(($usedGB / $totalGB) * 100, 2);
+        $usedPercent = $totalGB > 0.0
+            ? round(($usedGB / $totalGB) * 100, 2)
+            : 0.0;
 
         return "$usedGB GB / $totalGB GB ($usedPercent%)";
     }
@@ -734,9 +760,10 @@ private function getMagentoEnvironmentValue(string $name): ?string
     private function getValueFromDeploymentConfig($objectManager, string $name): ?string
     {
         try {
+            /** @var \Magento\Framework\App\DeploymentConfig $deploymentConfig */
             $deploymentConfig = $objectManager->get(\Magento\Framework\App\DeploymentConfig::class);
             $envValue = $deploymentConfig->get('system/default/environment/' . $name);
-            if ($envValue !== null) {
+            if ($envValue !== null && is_scalar($envValue)) {
                 return (string) $envValue;
             }
         } catch (\Exception $e) {
@@ -760,7 +787,7 @@ private function getValueFromEnvironmentService($objectManager, string $name): ?
         try {
             $environmentService = $objectManager->get(\Magento\Framework\App\EnvironmentInterface::class);
             $method = 'get' . str_replace(' ', '', ucwords(str_replace('_', ' ', strtolower($name))));
-            if (method_exists($environmentService, $method)) {
+            if (is_object($environmentService) && method_exists($environmentService, $method)) {
                 $value = $environmentService->$method();
                 if ($value !== null) {
                     return (string) $value;
diff --git a/src/Console/Command/System/CheckCommand.php.new b/src/Console/Command/System/CheckCommand.php.new
deleted file mode 100644
index e69de29..0000000
diff --git a/src/Console/Command/System/VersionCommand.php b/src/Console/Command/System/VersionCommand.php
index 9e58891..02f515c 100644
--- a/src/Console/Command/System/VersionCommand.php
+++ b/src/Console/Command/System/VersionCommand.php
@@ -73,7 +73,10 @@ private function getModuleVersion(): string
         try {
             $composerJson = $this->fileDriver->fileGetContents(__DIR__ . '/../../../../composer.json');
             $composerData = json_decode($composerJson, true);
-            return $composerData['version'] ?? self::UNKNOWN_VERSION;
+            if (is_array($composerData) && isset($composerData['version']) && is_string($composerData['version'])) {
+                return $composerData['version'];
+            }
+            return self::UNKNOWN_VERSION;
         } catch (\Exception $e) {
             return self::UNKNOWN_VERSION;
         }
@@ -96,7 +99,9 @@ private function getLatestVersion(): string
 
             if ($response->getStatusCode() === 200) {
                 $data = json_decode($response->getBody()->getContents(), true);
-                return $data['tag_name'] ?? self::UNKNOWN_VERSION;
+                if (is_array($data) && isset($data['tag_name']) && is_string($data['tag_name'])) {
+                    return $data['tag_name'];
+                }
             }
         } catch (\Exception $e) {
             if ($this->io->isVerbose()) {
diff --git a/src/Console/Command/Theme/BuildCommand.php b/src/Console/Command/Theme/BuildCommand.php
index 8d89536..c1558a9 100644
--- a/src/Console/Command/Theme/BuildCommand.php
+++ b/src/Console/Command/Theme/BuildCommand.php
@@ -65,6 +65,7 @@ protected function configure(): void
      */
     protected function executeCommand(InputInterface $input, OutputInterface $output): int
     {
+        /** @var array<string> $themeCodes */
         $themeCodes = $input->getArgument('themeCodes');
 
         // Allow wildcards using the AbstractCommand helper
@@ -97,7 +98,7 @@ protected function executeCommand(InputInterface $input, OutputInterface $output
                 label: 'Select themes to build',
                 options: fn(string $value) => empty($value)
                     ? $options
-                    : array_values(array_filter($options, fn($option) => stripos((string)$option, $value) !== false)),
+                    : array_values(array_filter($options, fn($option) => stripos((string) $option, $value) !== false)),
                 placeholder: 'Type to search theme...',
                 hint: 'Type to search, arrow keys to navigate, Space to toggle, Enter to confirm',
                 required: false,
@@ -106,6 +107,7 @@ protected function executeCommand(InputInterface $input, OutputInterface $output
             try {
                 $themeCodes = $themeCodesPrompt->prompt();
                 \Laravel\Prompts\Prompt::terminal()->restoreTty();
+                /** @var array<string> $themeCodes */
 
                 // Reset environment
                 $this->resetPromptEnvironment();
@@ -355,14 +357,14 @@ private function displayBuildSummary(SymfonyStyle $io, array $successList, float
             $io->success(sprintf(
                 '🚀 Successfully built %d theme(s). Build process completed in %.2f seconds.',
                 $successCount,
-                $duration
+                $duration,
             ));
             $io->writeln('Summary:');
             $io->newLine();
         } else {
             $io->warning(sprintf(
                 'Build process completed in %.2f seconds, but no themes were built successfully.',
-                $duration
+                $duration,
             ));
             return;
         }
diff --git a/src/Console/Command/Theme/CleanCommand.php b/src/Console/Command/Theme/CleanCommand.php
index 053ac26..569c6a2 100644
--- a/src/Console/Command/Theme/CleanCommand.php
+++ b/src/Console/Command/Theme/CleanCommand.php
@@ -70,7 +70,7 @@ protected function configure(): void
      */
     protected function executeCommand(InputInterface $input, OutputInterface $output): int
     {
-        $dryRun = $input->getOption('dry-run');
+        $dryRun = (bool) $input->getOption('dry-run');
 
         if ($dryRun) {
             $this->io->note('DRY RUN MODE: No files will be deleted');
@@ -98,6 +98,7 @@ protected function executeCommand(InputInterface $input, OutputInterface $output
      */
     private function resolveThemeCodes(InputInterface $input, OutputInterface $output): ?array
     {
+        /** @var array<string> $themeCodes */
         $themeCodes = $input->getArgument('themeCodes');
         $cleanAll = $input->getOption('all');
 
@@ -163,7 +164,7 @@ private function selectThemesInteractively(OutputInterface $output): ?array
     /**
      * Display available themes for non-interactive environments
      *
-     * @param array<mixed> $themes
+     * @param \Magento\Theme\Model\Theme[] $themes
      * @return void
      */
     private function displayAvailableThemes(array $themes): void
@@ -188,9 +189,9 @@ private function displayAvailableThemes(array $themes): void
     /**
      * Prompt user to select themes
      *
-     * @param array<string> $options
-     * @param array<mixed> $themes
-     * @return array<string>|null
+     * @param string[] $options
+     * @param \Magento\Theme\Model\Theme[] $themes
+     * @return string[]|null
      */
     private function promptForThemes(array $options, array $themes): ?array
     {
@@ -200,7 +201,7 @@ private function promptForThemes(array $options, array $themes): ?array
             label: 'Select themes to clean',
             options: fn(string $value) => empty($value)
                 ? $options
-                : array_values(array_filter($options, fn($option) => stripos((string)$option, $value) !== false)),
+                : array_values(array_filter($options, fn($option) => stripos((string) $option, $value) !== false)),
             placeholder: 'Type to search theme...',
             hint: 'Type to search, arrow keys to navigate, Space to toggle, Enter to confirm',
             required: false,
@@ -216,6 +217,7 @@ private function promptForThemes(array $options, array $themes): ?array
                 return null;
             }
 
+            /** @var array<string> $themeCodes */
             return $themeCodes;
         } catch (\Exception $e) {
             $this->resetPromptEnvironment();
@@ -231,7 +233,7 @@ private function promptForThemes(array $options, array $themes): ?array
      * @param array<string> $themeCodes
      * @param bool $dryRun
      * @param OutputInterface $output
-     * @return array<int, mixed> [totalCleaned, failedThemes]
+     * @return array{int, array<string>} [totalCleaned, failedThemes]
      */
     private function processThemes(array $themeCodes, bool $dryRun, OutputInterface $output): array
     {
diff --git a/src/Console/Command/Theme/TokensCommand.php b/src/Console/Command/Theme/TokensCommand.php
index f97684a..11a3b46 100644
--- a/src/Console/Command/Theme/TokensCommand.php
+++ b/src/Console/Command/Theme/TokensCommand.php
@@ -68,7 +68,8 @@ protected function configure(): void
      */
     protected function executeCommand(InputInterface $input, OutputInterface $output): int
     {
-        $themeCode = $this->selectTheme($input->getArgument('themeCode'));
+        $arg = $input->getArgument('themeCode');
+        $themeCode = $this->selectTheme(is_string($arg) ? $arg : null);
         if ($themeCode === null) {
             return Cli::RETURN_FAILURE;
         }
@@ -112,7 +113,7 @@ private function selectTheme(?string $themeCode): ?string
             label: 'Select theme to generate tokens for',
             options: fn(string $value) => empty($value)
                 ? $options
-                : array_values(array_filter($options, fn($option) => stripos((string)$option, $value) !== false)),
+                : array_values(array_filter($options, fn($option) => stripos((string) $option, $value) !== false)),
             placeholder: 'Type to search theme...',
             scroll: 10,
             hint: 'Type to search, arrow keys to navigate, Enter to confirm',
@@ -121,7 +122,7 @@ private function selectTheme(?string $themeCode): ?string
         try {
             $themeCode = $themeCodePrompt->prompt();
             \Laravel\Prompts\Prompt::terminal()->restoreTty();
-            return $themeCode;
+            return is_string($themeCode) ? $themeCode : null;
         } catch (\Exception $e) {
             $this->io->error('Interactive mode failed: ' . $e->getMessage());
             return null;
diff --git a/src/Console/Command/Theme/WatchCommand.php b/src/Console/Command/Theme/WatchCommand.php
index eea1da9..ce47cf7 100644
--- a/src/Console/Command/Theme/WatchCommand.php
+++ b/src/Console/Command/Theme/WatchCommand.php
@@ -77,7 +77,7 @@ protected function executeCommand(InputInterface $input, OutputInterface $output
                 label: 'Select theme to watch',
                 options: fn(string $value) => empty($value)
                     ? $options
-                    : array_values(array_filter($options, fn($option) => stripos((string)$option, $value) !== false)),
+                    : array_values(array_filter($options, fn($option) => stripos((string) $option, $value) !== false)),
                 placeholder: 'Type to search theme...',
                 scroll: 10,
                 hint: 'Type to search, arrow keys to navigate, Enter to confirm',
@@ -87,6 +87,11 @@ protected function executeCommand(InputInterface $input, OutputInterface $output
             \Laravel\Prompts\Prompt::terminal()->restoreTty();
         }
 
+        if (!is_string($themeCode)) {
+            $this->io->error('No valid theme code provided.');
+            return self::FAILURE;
+        }
+
         $themePath = $this->themePath->getPath($themeCode);
         if ($themePath === null) {
             // Try to suggest similar themes
diff --git a/src/Model/ThemeList.php b/src/Model/ThemeList.php
index c3219d7..939bbcb 100644
--- a/src/Model/ThemeList.php
+++ b/src/Model/ThemeList.php
@@ -5,6 +5,7 @@
 namespace OpenForgeProject\MageForge\Model;
 
 use Magento\Framework\View\Design\Theme\ThemeList as MagentoThemeList;
+use Magento\Theme\Model\Theme;
 
 class ThemeList
 {
@@ -21,10 +22,12 @@ public function __construct(
     /**
      * Get all themes
      *
-     * @return array<mixed>
+     * @return array<string, Theme>
      */
     public function getAllThemes(): array
     {
-        return $this->magentoThemeList->getItems();
+        /** @var array<string, Theme> $items */
+        $items = $this->magentoThemeList->getItems();
+        return $items;
     }
 }
diff --git a/src/Service/Hyva/CompatibilityChecker.php b/src/Service/Hyva/CompatibilityChecker.php
index de01676..d513639 100644
--- a/src/Service/Hyva/CompatibilityChecker.php
+++ b/src/Service/Hyva/CompatibilityChecker.php
@@ -14,6 +14,29 @@
  *
  * This service scans modules, detects incompatibilities with Hyvä theme framework,
  * and provides formatted results with summary statistics.
+ *
+ * @phpstan-import-type ScanIssue from IncompatibilityDetector
+ * @phpstan-import-type ScanResult from ModuleScanner
+ * @phpstan-import-type ModuleInfo from ModuleScanner
+ * @phpstan-type ModuleEntry array{
+ *     compatible: bool,
+ *     hasWarnings: bool,
+ *     scanResult: ScanResult,
+ *     moduleInfo: ModuleInfo
+ * }
+ * @phpstan-type CheckSummary array{
+ *     total: int,
+ *     compatible: int,
+ *     incompatible: int,
+ *     hyvaAware: int,
+ *     criticalIssues: int,
+ *     warningIssues: int
+ * }
+ * @phpstan-type CheckResults array{
+ *     modules: array<string, ModuleEntry>,
+ *     summary: CheckSummary,
+ *     hasIncompatibilities: bool
+ * }
  */
 class CompatibilityChecker
 {
@@ -37,7 +60,7 @@ public function __construct(
      * @param bool $excludeVendor Whether to exclude modules from the vendor/ directory
      * @return array<string, mixed> Results with structure: ['modules' => [], 'summary' => [],
      *     'hasIncompatibilities' => bool]
-     * @phpstan-return array{modules: array<string, mixed>, summary: array<string, int>, hasIncompatibilities: bool}
+     * @phpstan-return CheckResults
      */
     public function check(
         SymfonyStyle $io,
@@ -86,7 +109,6 @@ public function check(
             $hasWarnings = $scanResult['totalIssues'] > $scanResult['criticalIssues'];
 
             $results['modules'][$moduleName] = [
-                'path' => $modulePath,
                 'compatible' => $isCompatible,
                 'hasWarnings' => $hasWarnings,
                 'scanResult' => $scanResult,
@@ -140,7 +162,7 @@ private function isMagentoModule(string $moduleName): bool
      * Format results for display
      *
      * @param array $results
-     * @phpstan-param array<string, mixed> $results
+     * @phpstan-param CheckResults $results
      * @param bool $showAll
      * @return array<int, array<int, string>>
      */
@@ -168,7 +190,7 @@ public function formatResultsForDisplay(array $results, bool $showAll = false):
      * Get status display string with colors
      *
      * @param array $moduleData
-     * @phpstan-param array<string, mixed> $moduleData
+     * @phpstan-param ModuleEntry $moduleData
      * @return string
      */
     private function getStatusDisplay(array $moduleData): string
@@ -192,7 +214,7 @@ private function getStatusDisplay(array $moduleData): string
      * Get issues display string
      *
      * @param array $moduleData
-     * @phpstan-param array<string, mixed> $moduleData
+     * @phpstan-param ModuleEntry $moduleData
      * @return string
      */
     private function getIssuesDisplay(array $moduleData): string
@@ -223,21 +245,13 @@ private function getIssuesDisplay(array $moduleData): string
      *
      * @param string $moduleName
      * @param array $moduleData
-     * @phpstan-param array<string, mixed> $moduleData
-     * @return array<int, array<string, mixed>>
+     * @phpstan-param ModuleEntry $moduleData
+     * @return array<int, array{file: string, issues: array<int, ScanIssue>}>
      */
     public function getDetailedIssues(string $moduleName, array $moduleData): array
     {
-        // Safely access nested array structure
-        $scanResult = $moduleData['scanResult'] ?? [];
-        if (!is_array($scanResult)) {
-            return [];
-        }
-
-        $files = $scanResult['files'] ?? [];
-        if (!is_array($files)) {
-            return [];
-        }
+        $scanResult = $moduleData['scanResult'];
+        $files = $scanResult['files'];
 
         $details = [];
 
diff --git a/src/Service/Hyva/IncompatibilityDetector.php b/src/Service/Hyva/IncompatibilityDetector.php
index 5edce53..c3be313 100644
--- a/src/Service/Hyva/IncompatibilityDetector.php
+++ b/src/Service/Hyva/IncompatibilityDetector.php
@@ -11,6 +11,8 @@
  *
  * Uses pattern matching to identify RequireJS, Knockout.js, jQuery, and UI Components
  * usage that would be problematic in a Hyvä environment.
+ *
+ * @phpstan-type ScanIssue array{description: string, severity: string, line: int, pattern: string}
  */
 class IncompatibilityDetector
 {
@@ -107,6 +109,7 @@ public function __construct(
      *
      * @param string $filePath
      * @return array<int, array<string, mixed>> Array of issues with keys: pattern, description, severity, line
+     * @phpstan-return array<int, ScanIssue>
      */
     public function detectInFile(string $filePath): array
     {
@@ -153,8 +156,9 @@ private function mapExtensionToType(string $extension): string
      * @param array $lines
      * @param array $patterns
      * @return array<int, array<string, mixed>>
+     * @phpstan-return array<int, ScanIssue>
      * @phpstan-param array<int, string> $lines
-     * @phpstan-param array<int, array<string, mixed>> $patterns
+     * @phpstan-param array<int, array{pattern: string, description: string, severity: string}> $patterns
      */
     private function scanContentForPatterns(array $lines, array $patterns): array
     {
diff --git a/src/Service/Hyva/ModuleScanner.php b/src/Service/Hyva/ModuleScanner.php
index 2fb17bc..8b280da 100644
--- a/src/Service/Hyva/ModuleScanner.php
+++ b/src/Service/Hyva/ModuleScanner.php
@@ -11,6 +11,10 @@
  *
  * Recursively scans JavaScript, XML, and PHTML files within module directories
  * to identify patterns that may be incompatible with Hyvä themes.
+ *
+ * @phpstan-import-type ScanIssue from IncompatibilityDetector
+ * @phpstan-type ScanResult array{files: array<string, array<int, ScanIssue>>, totalIssues: int, criticalIssues: int}
+ * @phpstan-type ModuleInfo array{name: string, version: string, isHyvaAware: bool}
  */
 class ModuleScanner
 {
@@ -32,6 +36,7 @@ public function __construct(
      *
      * @param string $modulePath
      * @return array<string, mixed> Array with structure: ['files' => [], 'totalIssues' => int, 'criticalIssues' => int]
+     * @phpstan-return ScanResult
      */
     public function scanModule(string $modulePath): array
     {
@@ -120,14 +125,20 @@ private function isHyvaCompatibilityPackage(array $composerData): bool
     {
         // Check if this IS a Hyvä compatibility package
         $packageName = $composerData['name'] ?? '';
-        if (str_starts_with($packageName, 'hyva-themes/') && str_contains($packageName, '-compat')) {
+        if (is_string($packageName)
+            && str_starts_with($packageName, 'hyva-themes/')
+            && str_contains($packageName, '-compat')
+        ) {
             return true;
         }
 
         // Check dependencies for Hyvä packages
         $requires = $composerData['require'] ?? [];
+        if (!is_array($requires)) {
+            return false;
+        }
         foreach ($requires as $package => $version) {
-            if (str_starts_with($package, 'hyva-themes/')) {
+            if (is_string($package) && str_starts_with($package, 'hyva-themes/')) {
                 return true;
             }
         }
@@ -157,6 +168,7 @@ public function hasHyvaCompatibilityPackage(string $modulePath): bool
                 return false;
             }
 
+            /** @var array<string, mixed> $composerData */
             return $this->isHyvaCompatibilityPackage($composerData);
         } catch (\Exception $e) {
             return false;
@@ -168,6 +180,7 @@ public function hasHyvaCompatibilityPackage(string $modulePath): bool
      *
      * @param string $modulePath
      * @return array<string, mixed>
+     * @phpstan-return ModuleInfo
      */
     public function getModuleInfo(string $modulePath): array
     {
@@ -185,9 +198,10 @@ public function getModuleInfo(string $modulePath): array
                 return ['name' => 'Unknown', 'version' => 'Unknown', 'isHyvaAware' => false];
             }
 
+            /** @var array<string, mixed> $composerData */
             return [
-                'name' => $composerData['name'] ?? 'Unknown',
-                'version' => $composerData['version'] ?? 'Unknown',
+                'name' => is_string($composerData['name'] ?? null) ? $composerData['name'] : 'Unknown',
+                'version' => is_string($composerData['version'] ?? null) ? $composerData['version'] : 'Unknown',
                 'isHyvaAware' => $this->isHyvaCompatibilityPackage($composerData),
             ];
         } catch (\Exception $e) {
diff --git a/src/Service/ThemeBuilder/HyvaThemes/Builder.php b/src/Service/ThemeBuilder/HyvaThemes/Builder.php
index 4cb8ab0..c9043e4 100644
--- a/src/Service/ThemeBuilder/HyvaThemes/Builder.php
+++ b/src/Service/ThemeBuilder/HyvaThemes/Builder.php
@@ -68,7 +68,11 @@ public function detect(string $themePath): bool
         if ($this->fileDriver->isExists($themePath . '/composer.json')) {
             $composerContent = $this->fileDriver->fileGetContents($themePath . '/composer.json');
             $composerJson = json_decode($composerContent, true);
-            if (isset($composerJson['name']) && str_contains($composerJson['name'], 'hyva')) {
+            if (is_array($composerJson)
+                && isset($composerJson['name'])
+                && is_string($composerJson['name'])
+                && str_contains($composerJson['name'], 'hyva')
+            ) {
                 return true;
             }
         }
diff --git a/src/Service/ThemeBuilder/TailwindCSS/Builder.php b/src/Service/ThemeBuilder/TailwindCSS/Builder.php
index ed8789d..838006f 100644
--- a/src/Service/ThemeBuilder/TailwindCSS/Builder.php
+++ b/src/Service/ThemeBuilder/TailwindCSS/Builder.php
@@ -68,7 +68,11 @@ public function detect(string $themePath): bool
         if ($this->fileDriver->isExists($themePath . '/composer.json')) {
             $composerContent = $this->fileDriver->fileGetContents($themePath . '/composer.json');
             $composerJson = json_decode($composerContent, true);
-            if (!isset($composerJson['name']) && str_contains($composerJson['name'], 'hyva')) {
+            if (\is_array($composerJson)
+                && isset($composerJson['name'])
+                && \is_string($composerJson['name'])
+                && !str_contains($composerJson['name'], 'hyva')
+            ) {
                 return true;
             }
         }