fix: use log_step (cyan) for progress messages instead of log_warn (yellow) (#534)

~1500 progress messages across 481 files were using log_warn (yellow)
for normal status updates like "Installing...", "Setting up...",
"Creating server...", etc. This made users think something was wrong
when everything was proceeding normally.

Changes:
- Replace log_warn with log_step for all progress/status messages
- Keep log_warn only for actual warnings (errors, remediation hints)
- Remove emoji from 3 sprite completion messages

Agent: ux-engineer

Co-authored-by: A <6723574+louisgv@users.noreply.github.com>

upcloud/opencode.sh

@@ -19,7 +19,7 @@ create_server "${SERVER_NAME}"
 verify_server_connectivity "${UPCLOUD_SERVER_IP}"
 install_base_tools "${UPCLOUD_SERVER_IP}"
 
-log_warn "Installing OpenCode..."
+log_step "Installing OpenCode..."
 run_server "${UPCLOUD_SERVER_IP}" "$(opencode_install_cmd)"
 log_info "OpenCode installed"
 
@@ -30,7 +30,7 @@ else
     OPENROUTER_API_KEY=$(get_openrouter_api_key_oauth 5180)
 fi
 
-log_warn "Setting up environment variables..."
+log_step "Setting up environment variables..."
 inject_env_vars_ssh "${UPCLOUD_SERVER_IP}" upload_file run_server \
     "OPENROUTER_API_KEY=${OPENROUTER_API_KEY}"
 
@@ -39,7 +39,7 @@ log_info "UpCloud server setup completed successfully!"
 log_info "Server: ${SERVER_NAME} (UUID: ${UPCLOUD_SERVER_UUID}, IP: ${UPCLOUD_SERVER_IP})"
 echo ""
 
-log_warn "Starting OpenCode..."
+log_step "Starting OpenCode..."
 sleep 1
 clear
 interactive_session "${UPCLOUD_SERVER_IP}" "source ~/.zshrc && opencode"