diff --git a/scripts/cutover/start_go_stack.sh b/scripts/cutover/start_go_stack.sh
index d95de99..347f211 100755
--- a/scripts/cutover/start_go_stack.sh
+++ b/scripts/cutover/start_go_stack.sh
@@ -11,18 +11,29 @@
 # teardown + reads from `lakehouse-go-primary` — can run without
 # tearing down or polluting our long-running state.
 #
-# Two isolation layers:
+# Three isolation layers (the third was added 2026-05-01 after the
+# first push test exposed a port-collision bug — smoke catalogd
+# failed to bind :3212 because persistent catalogd already had it,
+# but smoke's poll_health 3212 succeeded responding to the
+# persistent daemon, and the smoke happily proceeded talking to
+# the persistent stack with the wrong bucket expectations):
+#
 #   1. BINARY NAMES — persistent stack runs via symlinks
 #      bin/persistent-<name> → bin/<name>. Smoke pkill pattern
-#      `bin/(storaged|...|gateway)` matches `bin/<name>` substrings;
+#      `bin/(storaged|...|gateway)$` matches `bin/<name>$` substrings;
 #      `bin/persistent-<name>` doesn't match because the slash is
 #      followed by 'p', not the daemon-name first letter.
 #   2. MINIO BUCKETS — persistent stack uses lakehouse-go-persistent;
 #      smoke harnesses use lakehouse-go-primary. Different buckets
 #      mean rehydrate paths can't see each other's `_vectors/*`
-#      persistence files. The temp toml at /tmp/lakehouse-persistent.toml
-#      overrides only [s3].bucket; everything else inherits from
-#      lakehouse.toml.
+#      persistence files.
+#   3. PORTS — persistent stack uses :4110 + :4211-:4219 (gateway +
+#      upstreams). Smoke harness uses :3110 + :3211-:3219. Both
+#      reach for the SAME chatd at :3220 because chatd is
+#      read-mostly (LLM dispatch, no persistent state to clobber)
+#      and operators don't want to maintain two LLM provider key
+#      sets. The temp toml at /tmp/lakehouse-persistent.toml
+#      overrides bucket + bind ports + upstream URLs (except chatd).
 #
 # Logs land in /tmp/gostack-logs/<bin>.log (one per daemon).
 #
@@ -70,10 +81,22 @@ if command -v mc >/dev/null 2>&1; then
   mc mb --ignore-existing "local/$PERSISTENT_BUCKET" >/dev/null 2>&1 || true
 fi
 
-# sed-replace the bucket line. Anchored to "lakehouse-go-primary" so
-# no other accidental "primary" mention gets touched.
-sed "s/lakehouse-go-primary/$PERSISTENT_BUCKET/g" lakehouse.toml > "$TEMP_TOML"
-echo "[gostack] config: $TEMP_TOML (bucket=$PERSISTENT_BUCKET)"
+# sed-replace the bucket line + port range. Anchored to specific
+# substrings so accidental matches don't fire. chatd's :3220 stays
+# unchanged (read-mostly LLM dispatch, no persistent state).
+sed -e "s/lakehouse-go-primary/$PERSISTENT_BUCKET/g" \
+    -e 's|127\.0\.0\.1:3110|127.0.0.1:4110|g' \
+    -e 's|127\.0\.0\.1:3211|127.0.0.1:4211|g' \
+    -e 's|127\.0\.0\.1:3212|127.0.0.1:4212|g' \
+    -e 's|127\.0\.0\.1:3213|127.0.0.1:4213|g' \
+    -e 's|127\.0\.0\.1:3214|127.0.0.1:4214|g' \
+    -e 's|127\.0\.0\.1:3215|127.0.0.1:4215|g' \
+    -e 's|127\.0\.0\.1:3216|127.0.0.1:4216|g' \
+    -e 's|127\.0\.0\.1:3217|127.0.0.1:4217|g' \
+    -e 's|127\.0\.0\.1:3218|127.0.0.1:4218|g' \
+    -e 's|127\.0\.0\.1:3219|127.0.0.1:4219|g' \
+    lakehouse.toml > "$TEMP_TOML"
+echo "[gostack] config: $TEMP_TOML (bucket=$PERSISTENT_BUCKET, ports=4110+4211-4219)"
 
 # ── Cleanup any prior persistent daemons ────────────────────────────
 # Match by the persistent- prefix so smoke processes are untouched.
@@ -100,17 +123,17 @@ start() {
   return 1
 }
 
-echo "[gostack] starting in dependency order"
-start storaged  3211
-start catalogd  3212
-start ingestd   3213
-start queryd    3214
-start embedd    3216
-start vectord   3215
-start pathwayd  3217
-start observerd 3219
-start matrixd   3218
-start gateway   3110
+echo "[gostack] starting in dependency order (port range :4xxx)"
+start storaged  4211
+start catalogd  4212
+start ingestd   4213
+start queryd    4214
+start embedd    4216
+start vectord   4215
+start pathwayd  4217
+start observerd 4219
+start matrixd   4218
+start gateway   4110
 
 # chatd is started independently — its provider key files come from
 # /etc/lakehouse/{ollama_cloud,openrouter,opencode,kimi}.env; if
@@ -132,11 +155,12 @@ fi
 
 echo
 echo "[gostack] ready · sweep:"
-for p in 3110 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220; do
+for p in 4110 4211 4212 4213 4214 4215 4216 4217 4218 4219 3220; do
   curl -sSf -m 1 "http://127.0.0.1:$p/health" 2>/dev/null | head -c 80
   echo
 done
 echo
-echo "[gostack] persistent stack uses bucket: $PERSISTENT_BUCKET"
-echo "[gostack] smoke harnesses use bucket:    lakehouse-go-primary"
+echo "[gostack] persistent stack: ports :4110+:4211-:4219 · bucket=$PERSISTENT_BUCKET"
+echo "[gostack] smoke harnesses:  ports :3110+:3211-:3219 · bucket=lakehouse-go-primary"
+echo "[gostack] shared:           chatd at :3220 (read-mostly LLM dispatch)"
 echo "[gostack] tear down via: pkill -f 'bin/persistent-'"