Start the Platform with its base path, which next start re-reads

The zone never became ready in CI: built with SIM_PLATFORM_BASE_PATH but started without it, next start re-reads the config and answered 404 for every route.

Author: waleedlatif1

.github/scripts/http-e2e.sh

@@ -160,7 +160,7 @@ start_platform() {
   local port=$1
   platform_tag="platform-$GITHUB_RUN_ID-$GITHUB_RUN_ATTEMPT-$$"
   platform_log="$report_dir/platform-live-platform.log"
-  E2E_APP="$platform_tag" SIM_PLATFORM_API_ORIGIN="$local_app_url" setsid node \
+  E2E_APP="$platform_tag" SIM_PLATFORM_API_ORIGIN="$local_app_url" SIM_PLATFORM_BASE_PATH=/org setsid node \
     ../../node_modules/next/dist/bin/next start platform --hostname 127.0.0.1 --port "$port" \
     > "$platform_log" 2>&1 &
   platform_pid=$!

apps/sim/platform/README.md

@@ -29,7 +29,7 @@ Deployed, the Platform is a zone at `/org` on the main app's origin, so it share
 
 | Variable | Set on | Purpose |
 | --- | --- | --- |
-| `SIM_PLATFORM_BASE_PATH=/org` | Platform, at build | Prefixes routes and assets |
+| `SIM_PLATFORM_BASE_PATH=/org` | Platform, at build and at `next start` | Prefixes routes and assets; `next start` re-reads the config, so without it every route answers 404 |
 | `SIM_PLATFORM_API_ORIGIN` | Platform, at runtime | Where server reads go, with the viewer's cookies |
 | `NEXT_PUBLIC_APP_URL` | Platform, at runtime | The main app's public origin, for login and legacy links |
 | `SIM_PLATFORM_ORIGIN` | Main app, at build and runtime | The `/org` rewrite is baked at build; the organization redirect reads it at runtime |