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

src/custom-model-injection.ts

@@ -56,6 +56,8 @@ export interface EnvInjection {
   apiKeyTrustFile?: { relPath: string; shape: 'claude-api-key-responses' };
   /** The literal API key value this injection used, for `apiKeyTrustFile` to pre-approve. */
   apiKey?: string;
+  /** See `customModelInjection.skipFirstRunPrompts` — carried through so the IO wrapper can seed it. */
+  skipFirstRunPrompts?: boolean;
 }
 
 export interface ConfigDirInjection {
@@ -122,6 +124,7 @@ export function buildCustomModelInjection(
       let result: EnvInjection = withLaunchModel({ kind: 'env', envOverrides }, cap.launchModel, modelId);
       if (cap.configDirVar) result = { ...result, configDirVar: cap.configDirVar };
       if (cap.apiKeyTrustFile) result = { ...result, apiKeyTrustFile: cap.apiKeyTrustFile, apiKey };
+      if (cap.skipFirstRunPrompts) result = { ...result, skipFirstRunPrompts: true };
       return result;
     }