refactor: standardize Java package layout

[ryanbarlow97]

Archaeo still uses com.nowko.archeology, outside the workspace package convention. Move all 121 Java source files to src/main/java/net/tfminecraft/archaeo/, update package references, and point plugin.yml at net.tfminecraft.archaeo.ArcheologyPlugin.

Validation:

• mvn clean verify passes before and after the change (no unit-test suite).
• Runtime JAR validation passes; the declared entry point exists and the old package is absent.
• Every Java file is identical after reversing package substitutions; other resources are unchanged.
• Workspace package check passes for all 38 plugins and 3,478 Java files.

Bump the API version to 2.0.0 because the package rename changes the public event class used by ActivityTF. Maven group/artifact identifiers, plugin identity, configuration and gameplay behavior are unchanged. The coordinated ActivityTF change pins 2.0.0 and must use the matching Archaeo release. No server deployment is included.