feat(custom-model): skip Claude Code's first-run wizard on custom-model launches

A fresh, isolated CLAUDE_CONFIG_DIR (used to keep an injected API key
away from a stored claude.ai OAuth login) looks like a brand-new Claude
Code profile to the CLI, so it replays its ENTIRE first-run sequence on
every single launch: the theme picker, the security-notes screen, the
per-project "trust this folder?" dialog, and (running with
--dangerously-skip-permissions) a one-time bypass-permissions warning —
confirmed live, none of which a real, already-onboarded profile shows
again.

- New registry-declared env-kind field `skipFirstRunPrompts` (alongside
  apiKeyTrustFile, which it reuses) — claude's entry only, carried
  through buildCustomModelInjection (pure) into
  applyCustomModelInjection (IO).
- seedFirstRunOnboardingState(): merges hasCompletedOnboarding: true and
  this session's own projects[workingDir].hasTrustDialogAccepted: true
  into the same <configDir>/.claude.json the API-key trust file already
  writes to — other projects and other fields on this session's own
  entry are left untouched.
- seedSkipBypassPermissionsPrompt(): merges
  skipDangerousModePermissionPrompt: true into <configDir>/settings.json,
  a separate file, same corrupt-tolerant merge behavior.
- applyCustomModelInjection() gains an optional workingDir parameter,
  threaded from session.workingDir (dedicated apply route) /
  resolvedCasePath (quick-start route) — boot recovery omits it
  (a dialog already answered once needs no re-seed on the same,
  persisted isolated directory).

Tests added at the pure-builder, IO-wrapper (including merge-preserves-
other-fields and corrupt-file-tolerance cases), and existing directory-
listing assertions updated for the new settings.json file. Typecheck/
lint/format clean; full suite shows no new regressions (baseline
pre-existing Windows-environment failures unchanged, 8 more passing
tests than before — the ones added here).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RqZeHrRS6DYcGcGX2p9EwG

.changeset/run-menu-custom-model-picker.md

@@ -13,6 +13,10 @@ Everything below was found and fixed against a **real llama-swap server**, not j
 - **Context floor too small for Claude Code to even start.** Fixing the overflow above surfaced a second, unfixable-by-injection failure: Claude Code's own system prompt and tool schemas cost roughly 36.4K tokens on their own (confirmed live via an `in:0 out:0` failure on the very first message), which can exceed a small model's entire real context before any conversation history exists to trim — no `CLAUDE_CODE_MAX_CONTEXT_TOKENS` value fixes that, since it only governs when history gets compacted. Applying such a model now returns a warning (gated on the CLI registry declaring a `contextLengthVar`, so it's a no-op for every other harness) instead of launching straight into a guaranteed first-message failure, and the Run-menu picker shows it as an in-app dialog naming the model, its discovered context and the ~40K safe floor, with the actual fix spelled out: give the model an explicit larger `-c`/`--ctx-size` in llama-swap's config instead of relying on auto-fit, which optimizes for the biggest model that fits rather than the biggest context. "Launch anyway" is still one click away.
 - **The real root cause of "it still says opus, not my model."** llama.cpp runs exactly one model at a time; llama-swap unloads and reloads it on demand, which can take anywhere from a few seconds to well over a minute — long enough that a session mid-swap is indistinguishable from one that never left the native backend. Applying a selection now checks llama-swap's own `GET /running` first (feature-detected; a plain llama.cpp/OpenAI-compatible server has no such endpoint and is never checked); if switching would unload a model **another live session is actively using**, the apply is refused with a warning naming that session instead of silently switching, and a confirmation retry proceeds anyway. Either way, a sticky "loading model…" toast now covers the actual swap window until llama-swap reports the target model ready, so a prompt sent mid-swap reads as "loading," never as silence or an answer from whatever was loaded a moment before.
 
+- **Claude's whole first-run sequence, on every single launch.** A fresh, otherwise-empty `CLAUDE_CONFIG_DIR` isn't just missing the API-key approval above — Claude Code treats it as a brand-new profile and replays the theme picker, the security-notes screen, the per-project "trust this folder?" dialog, and (running bypassed) a one-time permissions-bypass warning, every time, confirmed live. None of that shows up again for a real, already-onboarded profile. `customModelInjection`'s new `skipFirstRunPrompts` (claude's entry only) pre-seeds that same "already been through this" state — `hasCompletedOnboarding` and this session's own project trust into the same `.claude.json` the API-key approval merges into, `skipDangerousModePermissionPrompt` into `settings.json` — so a custom-model launch reaches the conversation exactly as fast as a native cloud one, with nobody there to click through a wizard.
+
+Two more, from actually clicking through the swap-confirm and context-warning dialogs live: their z-index sat under the centred status banner, so a dialog could render fully hidden behind "Claude started — switching to llama-swap…"; and their Cancel/confirm buttons stacked instead of sitting side by side (`.btn-toolbar`'s own `display: flex` needs a row-layout parent it never had). Both dialogs now clear the banner and lay their buttons out centred, side by side.
+
 Remote (SSH) and Docker sessions are refused for now (400) — their restart reattaches the durable remote/in-container tmux rather than relaunching the agent.
 
 **One more, from watching it launch live: opencode, Codex, Gemini, Pi, Grok, DeepSeek and OMP now launch directly on the endpoint, with no restart at all.** Picking one of these seven from the Run-menu picker used to launch natively first, wait for it to settle, then restart it in place with the endpoint applied — a deliberate two-step design, but visibly a native boot immediately followed by a second one, worst on a CLI whose TUI fully reinitializes on a restart (confirmed live on Codex). `POST /api/quick-start` now accepts a `customModel` field and computes the same injection _before_ the session exists, launching straight onto the endpoint the first time — no visible relaunch, and it also runs the same llama-swap conflict check (warns before unloading a model another live session is using) at create time. Claude still uses the original launch-then-restart path for now (its own `--resume`-based restart is far less jarring, and `runClaude()`'s multi-tab and docker-config-drift-retry logic make folding it into the one-shot path separate work).