Document the remote browser as the way the suite is run

README.md

@@ -403,10 +403,9 @@ npm run lint         # ESLint, type-aware; --fix for the fixable half
 npm run format       # Prettier over src, tests and tools
 npm run check        # typecheck + lint + format:check + tests, what CI would run
 npm run build        # writes dist/ and regenerates index.html
+export GM_REMOTE=user@host                                    # where the browser runs; see below
 node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 267 editor checks, screenshots in /tmp/gm-e2e-*.png
 node tools/seed-jumprun.mjs && node tools/smoke-jumprun.mjs   # 24 checks: the example game, played end to end
-
-GM_REMOTE=user@host node tools/e2e.mjs                        # run the browser on another machine
 ```
 
 **A run needs a working GPU.** An idle editor page keeps rendering a picture that never changes, and
@@ -422,7 +421,9 @@ over SSH and forwards its CDP port back to `127.0.0.1`, so the harness itself is
 checks load the public base URL, so the remote side needs only a browser and internet: no repo, no
 node. Setup is an SSH key (`GM_REMOTE_KEY`, default `~/.ssh/gm-win.key`). Measured against a Windows
 desktop with an RTX 4070: **267 checks in 128 s and 24 smoke checks in 16 s, with this machine idle**
-(0.4 s of CPU for the whole smoke run, load average 0.04).
+(0.4 s of CPU for the whole smoke run, load average 0.04). **That is how the suite is meant to be
+run here.** A local run works and costs 124 s, but it pins the development box – set `GM_REMOTE` and
+leave it set; without a reachable host, do not fall back to local, fix the host.
 
 `tools/remote/gm-browser.ps1` is copied over on every run, and getting the browser to die with the
 run took three tries, because two obvious leashes do not hold on Windows: