docs: surface ios-qa CLIs + add end-to-end how-to walkthrough

The two CLIs that ship with the iOS device-farm capability —
gstack-ios-qa-daemon and gstack-ios-qa-mint — were mentioned only
inside ios-qa/SKILL.md. Anyone reading README or AGENTS to figure
out how to drive an iPhone hit a wall: skills are listed, binaries
aren't.

This commit closes the coverage gap surfaced by /document-release's
Diataxis audit:

- README.md, AGENTS.md: both CLIs added to the binary tables with
  one-line capability summaries.
- docs/howto-ios-testing-with-gstack.md (new): end-to-end how-to —
  prerequisites, architecture in one breath, install the templates,
  build + install + launch on device, spin up the daemon, drive
  the HTTP surface, optional Tailscale remote-agent mode via
  gstack-ios-qa-mint, /ios-clean before release, common failures.
  Pulled directly from the real iPhone 17 Pro Max / iOS 26.5
  verification run.
- README + AGENTS link to the new how-to from the iOS skill row.

No CHANGELOG entry change — the consolidated 1.43.0.0 entry is /ship
work. No VERSION bump — already at 1.43.0.0 covering all branch work.

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

README.md

@@ -230,7 +230,7 @@ Each skill feeds into the next. `/office-hours` writes a design doc that `/plan-
 | `/sync-gbrain` | **Keep Brain Current** — re-index this repo's code into gbrain via `gbrain sources add` + `gbrain sync --strategy code`, refresh the `## GBrain Search Guidance` block in CLAUDE.md, and auto-remove guidance when the capability check fails. `--incremental` (default), `--full`, `--dry-run`. Idempotent; safe to re-run. |
 | `/gstack-upgrade` | **Self-Updater** — upgrade gstack to latest. Detects global vs vendored install, syncs both, shows what changed. |
 | `/ios-qa` | **iOS Live-Device QA (v1.40+)** — drive a real iPhone over USB CoreDevice via an embedded `StateServer` in the app. Read Swift source, codegen typed `@Observable` accessors, run the agent loop. Optional `--tailnet` flag turns your Mac mini into a DIY device farm reachable by OpenClaw or any HTTP-capable agent on your Tailscale tailnet. Capability-tier allowlist (observe/interact/mutate/restore), per-device session lock, audit log. |
-| `/ios-fix`, `/ios-design-review`, `/ios-clean`, `/ios-sync` | iOS bug-fix loop, designer's-eye HIG audit, debug-bridge cleanup, and accessor resync. See `docs/skills.md`. |
+| `/ios-fix`, `/ios-design-review`, `/ios-clean`, `/ios-sync` | iOS bug-fix loop, designer's-eye HIG audit, debug-bridge cleanup, and accessor resync. See `docs/skills.md`. End-to-end walkthrough: [docs/howto-ios-testing-with-gstack.md](docs/howto-ios-testing-with-gstack.md). |
 
 ### New binaries (v0.19)
 
@@ -240,6 +240,8 @@ Beyond the slash-command skills, gstack ships standalone CLIs for workflows that
 |---------|-------------|
 | `gstack-model-benchmark` | **Cross-model benchmark** — run the same prompt through Claude, GPT (via Codex CLI), and Gemini; compare latency, tokens, cost, and (optionally) LLM-judge quality score. Auth detected per provider, unavailable providers skip cleanly. Output as table, JSON, or markdown. `--dry-run` validates flags + auth without spending API calls. |
 | `gstack-taste-update` | **Design taste learning** — writes approvals and rejections from `/design-shotgun` into a persistent per-project taste profile. Decays 5%/week. Feeds back into future variant generation so the system learns what you actually pick. |
+| `gstack-ios-qa-daemon` | **iOS device-farm daemon** — Mac-side broker between an agent and a connected iPhone over USB CoreDevice. Loopback by default; `--tailnet` opens a Tailscale-facing listener with identity-gated capability tiers. Single-instance via flock on `~/.gstack/ios-qa-daemon.pid`. See [docs/howto-ios-testing-with-gstack.md](docs/howto-ios-testing-with-gstack.md). |
+| `gstack-ios-qa-mint` | **iOS allowlist manager** — owner-grant CLI for the tailnet allowlist. `grant`/`revoke`/`list` against `~/.gstack/ios-qa-allowlist.json` (mode 0600). Remote agents never auto-allowlist; this is the explicit-intent path. |
 
 ### Continuous checkpoint mode (opt-in, local by default)