chore: rename contact email hello@axme.ai to contact@axme.ai (#33)

Coordinated rename of public contact email across all AXME repositories,
websites, docs, SDK metadata, and CLI/server user-facing messages.

#!axme pr=none repo=AxmeAI/axme-sdk-java

Author: George-iam

README.md

@@ -121,4 +121,4 @@ mvn test
 
 ---
 
-[hello@axme.ai](mailto:hello@axme.ai) · [Security](SECURITY.md) · [License](LICENSE)
+[contact@axme.ai](mailto:contact@axme.ai) · [Security](SECURITY.md) · [License](LICENSE)

pom.xml

@@ -23,7 +23,7 @@
     <developer>
       <id>axmeai</id>
       <name>AxmeAI</name>
-      <email>hello@axme.ai</email>
+      <email>contact@axme.ai</email>
       <organization>AxmeAI</organization>
       <organizationUrl>https://axme.ai</organizationUrl>
     </developer>