chore: sync local Mosaic changes

install.sh

@@ -151,6 +151,18 @@ else
   warn "Runtime asset linking failed (non-fatal)"
 fi
 
+if "$TARGET_DIR/bin/mosaic-ensure-sequential-thinking" >/dev/null 2>&1; then
+  ok "sequential-thinking MCP configured"
+else
+  if [[ "${MOSAIC_ALLOW_MISSING_SEQUENTIAL_THINKING:-0}" == "1" ]]; then
+    warn "sequential-thinking MCP setup failed but bypassed (MOSAIC_ALLOW_MISSING_SEQUENTIAL_THINKING=1)"
+  else
+    fail "sequential-thinking MCP setup failed (hard requirement)."
+    fail "Set MOSAIC_ALLOW_MISSING_SEQUENTIAL_THINKING=1 only for temporary bypass scenarios."
+    exit 1
+  fi
+fi
+
 if [[ "${MOSAIC_SKIP_SKILLS_SYNC:-0}" == "1" ]]; then
   ok "Skills sync skipped (MOSAIC_SKIP_SKILLS_SYNC=1)"
 else