Add support for pre-configured runners from environment variables

- Added RUNNERS env var to .env.example (comma-separated runner names)
- Updated supervisor binary to accept --runners flag
- Runners are automatically registered on startup using first admin secret
- Updated run.sh to pass RUNNERS from env to supervisor binary

scripts/run.sh

@@ -93,6 +93,11 @@ if [ ! -z "$MYCELIUM_URL" ]; then
     SUPERVISOR_CMD="$SUPERVISOR_CMD --mycelium-url $MYCELIUM_URL"
 fi
 
+# Add runners if provided
+if [ ! -z "$RUNNERS" ]; then
+    SUPERVISOR_CMD="$SUPERVISOR_CMD --runners $RUNNERS"
+fi
+
 RUST_LOG="$LOG_LEVEL" RUST_LOG_STYLE=never $SUPERVISOR_CMD > /tmp/supervisor-run.log 2>&1 &
 SUPERVISOR_PID=$!