Fix race condition: wait for container ready before launching CS Core

podman run -d returns before the container process is running.
CS Core's claude-code check immediately calls our wrapper, which
found the container not yet running and exited 1 — causing the
"claude-code not found" error.

Add a poll loop (10 x 0.5s) that waits for State.Running=true
before setting PATH and launching CS Core.

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

lib/container.sh

@@ -82,7 +82,20 @@ echo "→ Starting agents container '\$CONTAINER_NAME'..."
     "\$IMAGE_NAME" \\
     sleep infinity
 
-echo "→ Container ready."
+# ── Wait for container to be running ────────────────────────────────────
+echo -n "→ Waiting for container..."
+for _i in 1 2 3 4 5 6 7 8 9 10; do
+    if "\$RUNTIME" container inspect "\$CONTAINER_NAME" --format '{{.State.Running}}' 2>/dev/null | grep -q true; then
+        echo " ready."
+        break
+    fi
+    echo -n "."
+    sleep 0.5
+done
+if ! "\$RUNTIME" container inspect "\$CONTAINER_NAME" --format '{{.State.Running}}' 2>/dev/null | grep -q true; then
+    echo ""
+    echo "Error: container failed to start." >&2; exit 1
+fi
 
 # ── Put claude wrapper first on PATH ────────────────────────────────────
 export PATH="\$PROJECT_DIR/bin:\$PATH"