refactor: Extract ENV_TEMP pattern to inject_env_vars_ssh (SSH providers)

Converted 34 scripts across 6 SSH-based providers to use inject_env_vars_ssh:
- digitalocean: amazonq, cline, gemini (3 scripts)
- hetzner: amazonq, cline, gemini (3 scripts)
- linode: amazonq, cline, gemini (3 scripts)
- vultr: amazonq, cline, gemini (3 scripts)
- aws-lightsail: all agents except openclaw (10 scripts)
- lambda: all agents except openclaw (10 scripts)

Plus aws-lightsail/openclaw and lambda/openclaw (2 scripts)

Each conversion replaces 11-15 lines of temp file management with a single
inject_env_vars_ssh call that handles creation, upload, sourcing, and cleanup.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

lambda/gptme.sh

@@ -49,15 +49,8 @@ MODEL_ID="${MODEL_ID:-openrouter/auto}"
 # 8. Inject environment variables into ~/.zshrc
 log_warn "Setting up environment variables..."
 
-ENV_TEMP=$(mktemp)
-cat > "$ENV_TEMP" << EOF
-
-# [spawn:env]
-export OPENROUTER_API_KEY="${OPENROUTER_API_KEY}"
-EOF
-
-upload_file "$LAMBDA_SERVER_IP" "$ENV_TEMP" "/tmp/env_config"
-run_server "$LAMBDA_SERVER_IP" "cat /tmp/env_config >> ~/.zshrc && rm /tmp/env_config"
+inject_env_vars_ssh "${LAMBDA_INSTANCE_IP}" upload_file run_server \
+    "OPENROUTER_API_KEY=${OPENROUTER_API_KEY}"
 rm "$ENV_TEMP"
 
 echo ""