docs: keep the internal staging default out of the public example

The example's job is to show the value a reader should use. Explaining
that build.gradle.kts falls back to Simular's internal staging gateway
belongs where a contributor would look for it — the README key table and
SAI_GLASSES_APP.md both still say it, and why — not in the file every
fork copies.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: jamie-simular

meta-android-app/local.properties.example

@@ -41,12 +41,7 @@ gemini_api_key=
 # The Sai API base — the public production host, and the one to use unless you work at Simular. The
 # app calls /v1/agents/* over HTTPS, so no `adb reverse` is needed. This is only for reaching your Sai
 # AGENT; the voice conversation itself needs nothing from it and costs you nothing here.
-#
-# `build.gradle.kts` still DEFAULTS to the shared staging gateway
-# (https://staging.cloud-api.simular.cloud) when this is unset, which resolves to a private address
-# and is reachable only from inside Simular's network. That default is deliberate — a build with no
-# configuration should not quietly start billing production — but it is why an unset value looks like
-# a dead network rather than a missing setting.
+
 sai_api_url=https://api.sai.simular.ai
 
 # ── Required to RUN: Google sign-in (Firebase ID token) ──────────────────────────────────────────