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>

dependency-reduced-pom.xml

@@ -4,7 +4,7 @@
   <groupId>pt.henrique</groupId>
   <artifactId>communitymarket</artifactId>
   <name>CommunityMarket</name>
-  <version>1.0.0</version>
+  <version>2.1.0</version>
   <description>A comprehensive player-to-player marketplace plugin with sales, auctions, and negotiations</description>
   <build>
     <resources>
@@ -72,7 +72,7 @@
     <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>
     <dependency>
@@ -84,7 +84,7 @@
   </dependencies>
   <properties>
     <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>
     <maven.compiler.target>25</maven.compiler.target>
     <maven.compiler.source>25</maven.compiler.source>
   </properties>