fix(api): let node size its heap from the container limit (#2236)

deploy/self-hosting/.env.example

@@ -79,12 +79,12 @@ FLUXER_DISCOVERY_ENABLED=true
 #FLUXER_GATEWAY_MEMORY_LIMIT=1gb
 #FLUXER_MEILISEARCH_MEMORY_LIMIT=768mb
 
-# The Node heap ceiling must stay below the container limit above, with room to
-# spare: V8 adds roughly 200 MB of semi-space on top of the value set here, and
-# buffers live outside the heap entirely. Around 70 percent of the container limit
-# is a safe ratio. If the heap ceiling exceeds the container limit, the kernel
-# OOM-kills the container (exit 137, no diagnostics) instead of Node reporting a
-# JavaScript heap out of memory error you can act on.
+# Node sizes its own heap from the container memory limit by default, at roughly
+# 55 percent of it, which always leaves room for the buffers and stacks that live
+# outside the heap. Leave these unset unless you have a reason to pin the value.
+# Any value set here must stay well below the container limit above: a heap ceiling
+# above the container limit makes the kernel OOM-kill the container (exit 137, no
+# diagnostics) instead of Node reporting a JavaScript heap out of memory error.
 #FLUXER_API_NODE_HEAP_MB=1792
 #FLUXER_WORKER_NODE_HEAP_MB=1792