Harden remaining recruit action packets

[kaiserproger]

Summary

• Routes remaining group-wide recruit action packets through server-resolved command targets from the command authority branch.
• Hardens ranged fire, shields, rest, clear target/upkeep, protect, upkeep, mount/dismount, and formation-follow persistence against client-supplied sender/group UUID spoofing.
• Preserves owner transfer and faction-leader takeover behavior while adding server authority checks; gates spawn-egg writing to creative/admin senders.

Verification

• source ~/.sdkman/bin/sdkman-init.sh && ./gradlew compileJava
• code-simplifier cleanup pass completed; post-cleanup compile passed.
• code-reviewer findings resolved: faction takeover preserved, spawn egg minting gated server-side.

Stack

• Base branch: feature/command-pipeline-authority / PR Harden recruit command authority #62.
• This PR should be reviewed after or alongside PR Harden recruit command authority #62.