Port to Paper 26.3 (2.1.0)

Built against paper-api 26.3.build.140-beta on Java 25, api-version 26.3,
version 2.1.0 so the jar reports the number Modrinth shows. Release notes
are in the 2.1.0 section of the Modrinth changelog.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>pt.henrique</groupId>
     <artifactId>communitymarket</artifactId>
-    <version>1.0.0</version>
+    <version>2.1.0</version>
     <packaging>jar</packaging>
 
     <name>CommunityMarket</name>
@@ -16,7 +16,7 @@
         <maven.compiler.source>25</maven.compiler.source>
         <maven.compiler.target>25</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <paper.version>26.2.build.100-stable</paper.version>
+        <paper.version>26.3.build.140-beta</paper.version>
     </properties>
 
     <repositories>
@@ -37,7 +37,7 @@
         <dependency>
             <groupId>io.papermc.paper</groupId>
             <artifactId>paper-api</artifactId>
-            <version>26.2.build.100-stable</version>
+            <version>26.3.build.140-beta</version>
             <scope>provided</scope>
         </dependency>