fix: move HAPPY_HOME_DIR to /workspace so lock never persists across restarts

The daemon.state.json.lock lives on the home PVC and survives pod
restarts, causing happy daemon start to fail on every reboot. Moving
HAPPY_HOME_DIR to /workspace (emptyDir) means the entire happy state
directory is ephemeral and always clean on startup.

The rm -f in init-repo.sh is kept as a safety net for the within-run
case but is now a no-op on fresh starts.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

chart/values.yaml

@@ -12,7 +12,7 @@ githubRepo: ""
 # Happy Coder endpoints
 happyServerUrl: "https://happy.farh.net"
 happyWebappUrl: "https://happy-coder.farh.net"
-happyHomeDir: "/home/user/.happy"
+happyHomeDir: "/workspace/.happy"
 happyExperimental: "true"
 
 # VNC display