fix: pre-landing review fixes

Restore the /setup-gbrain code block the README split left open: README.md kept
the ```bash opener and docs/gbrain-quick-tour.md got only the closing fence, so
both pages rendered their body as one code block. Drop the self-referential
'Full reference' link in docs/domain-skills.md and make the troubleshooting
quick-answer link an in-page anchor.

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

README.md

@@ -208,6 +208,8 @@ Beyond the slash commands, gstack ships standalone CLIs (`gstack-egress`, `gstac
 [GBrain](https://github.com/garrytan/gbrain) is a persistent knowledge base for AI agents — think of it as the memory your agent actually keeps between sessions. GStack gives you a one-command path from zero to "it's running, my agent can call it."
 
 ```bash
+/setup-gbrain
+```
 
 The four setup paths, the per-repo trust policy and memory sync, in brief: [docs/gbrain-quick-tour.md](docs/gbrain-quick-tour.md). **Full monty — every scenario, every flag, every bin helper, every troubleshooting step:** [USING_GBRAIN_WITH_GSTACK.md](USING_GBRAIN_WITH_GSTACK.md)
 

docs/domain-skills.md

@@ -128,7 +128,7 @@ Hostname only — no body content, no agent text. Disable entirely with
 
 Two browser primitives in gstack's own engine (the fallback path when Aside isn't there) compound the agent over time:
 
-- **`$B domain-skill save`** — agent saves a per-site note (e.g., "LinkedIn's Apply button lives in an iframe") that fires automatically next time it visits that hostname. Quarantined → active after 3 successful uses → optional cross-project promotion via `$B domain-skill promote-to-global`. Storage lives alongside `/learn`'s per-project learnings file. Full reference: **[docs/domain-skills.md](domain-skills.md)**.
+- **`$B domain-skill save`** — agent saves a per-site note (e.g., "LinkedIn's Apply button lives in an iframe") that fires automatically next time it visits that hostname. Quarantined → active after 3 successful uses → optional cross-project promotion via `$B domain-skill promote-to-global`. Storage lives alongside `/learn`'s per-project learnings file.
 - **`$B cdp <Domain.method>`** — raw Chrome DevTools Protocol escape hatch for the rare case curated commands miss. Deny-default: methods must be explicitly added to `browse/src/cdp-allowlist.ts` with a one-line justification. Two-tier mutex serializes browser-scoped CDP calls against per-tab work. Output for data-exfil methods is wrapped in the UNTRUSTED envelope.
 
 > Want raw CDP with no rails, no allowlist, no daemon — just thin transport from agent to Chrome? [browser-use/browser-harness-js](https://github.com/browser-use/browser-harness-js) is a different philosophy (agent-authored helpers vs gstack's curated commands) and a good fit if you don't want gstack's security stack. The two can coexist: gstack's `$B cdp` and harness can both attach to the same Chrome via Playwright's `newCDPSession`.

docs/gbrain-quick-tour.md

@@ -2,6 +2,8 @@
 
 The short version of [USING_GBRAIN_WITH_GSTACK.md](../USING_GBRAIN_WITH_GSTACK.md), which has every scenario, flag, helper bin and troubleshooting step. This page is what the README used to say.
 
+```bash
+/setup-gbrain
 ```
 
 Four paths, pick one:

docs/troubleshooting.md

@@ -4231,7 +4231,7 @@ it. The usual fix is to re-run setup from that row's source for that host, e.g.
 A project install lives in the project's `.claude/skills/gstack` or
 `.agents/skills/gstack`; run its `setup` from inside the project.
 
-**Cursor freezes on load, or an agent's gstack skills went missing after an upgrade?** Each checkout now renders skills only for the agents installed from it (#1694). `./setup --status` lists them; `./setup --host <name>` adds one back. Pruned copies are in `~/.gstack/backups/host-renders/<time>-<id>/`, with every path in its `prune.log` ([troubleshooting](troubleshooting.md#host-renders-pruned)).
+**Cursor freezes on load, or an agent's gstack skills went missing after an upgrade?** Each checkout now renders skills only for the agents installed from it (#1694). `./setup --status` lists them; `./setup --host <name>` adds one back. Pruned copies are in `~/.gstack/backups/host-renders/<time>-<id>/`, with every path in its `prune.log` ([host renders pruned](#host-renders-pruned)).
 
 **`/browse` (or `/qa`, `/design-review`) says `NEEDS_ASIDE` or `ASIDE_NOT_RUNNING`?** That's the probe telling you it's about to use the fallback browser. Want Aside? Open the app and sign in — `aside --version` should print a version and `aside repl 'console.log("ok")'` should print `ok` — then re-run. gstack never installs it for you. Want the fallback on purpose while Aside is open? `GSTACK_SKIP_ASIDE=1` makes every skill, the renderer, and `./setup` treat Aside as absent. When Aside is absent the probe prints `NEEDS_ASIDE: <OS>` and skills trust that line for the macOS-only download pitch; `GSTACK_PLATFORM` overrides the OS it names, for tests and unusual hosts (set it in your shell — gstack never reads it from a project `.env`).