Add inline editing for licenses and copy license key button

- Add inline editing for status, expiry date, and domain fields
- Add copy-to-clipboard button for license keys
- Add AJAX handlers for inline editing with nonce verification
- Update LicenseManager with updateLicenseExpiry method
- Add new translations for inline editing strings (de_CH)
- Compile updated German translations to .mo file

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/License/LicenseManager.php

@@ -424,6 +424,39 @@ class LicenseManager
         return $result !== false;
     }
 
+    /**
+     * Update license expiry date
+     *
+     * @param int $licenseId License ID
+     * @param \DateTimeImmutable $expiresAt New expiry date
+     * @return bool Success
+     */
+    public function updateLicenseExpiry(int $licenseId, \DateTimeImmutable $expiresAt): bool
+    {
+        global $wpdb;
+
+        $license = $this->getLicenseById($licenseId);
+        if (!$license) {
+            return false;
+        }
+
+        $tableName = Installer::getLicensesTable();
+        $result = $wpdb->update(
+            $tableName,
+            ['expires_at' => $expiresAt->format('Y-m-d H:i:s')],
+            ['id' => $licenseId],
+            ['%s'],
+            ['%d']
+        );
+
+        // If license was expired and new date is in the future, reactivate it
+        if ($result !== false && $license->getStatus() === License::STATUS_EXPIRED && $expiresAt > new \DateTimeImmutable()) {
+            $this->updateLicenseStatus($licenseId, License::STATUS_ACTIVE);
+        }
+
+        return $result !== false;
+    }
+
     /**
      * Update license domain
      */