Document RENDERER_PORT, LOG_LEVEL, WORKERS_COUNT in .env.example

app.yml and the renderer launcher read three additional env vars that
.env.example didn't mention, leaving developers with no single place
to see which renderer knobs exist. Add them commented-out with their
defaults and brief descriptions.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: ihabadham

.env.example

@@ -9,3 +9,14 @@ RENDERER_PASSWORD=
 
 # Node renderer endpoint. Defaults to http://localhost:3800.
 # RENDERER_URL=http://localhost:3800
+
+# Port the Node renderer listens on. Defaults to 3800.
+# RENDERER_PORT=3800
+
+# Log verbosity for the Node renderer (debug, info, warn, error).
+# Defaults to info.
+# RENDERER_LOG_LEVEL=info
+
+# Number of renderer worker processes. `0` is single-process mode, useful
+# for local debugging. Defaults to 3; the app's CI workflow caps to 2.
+# RENDERER_WORKERS_COUNT=3