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/web/routes/session-routes.ts

@@ -1272,7 +1272,14 @@ export function registerSessionRoutes(
     // fails its pattern rather than quoting it, which would silently launch the CLI on its
     // own default provider again, so refuse an id the pattern cannot carry up front.
     const modelSpec = entry.launch.params.model;
-    const applied = applyCustomModelInjection(entry, endpoint, body.modelId, session.id, contextLength);
+    const applied = applyCustomModelInjection(
+      entry,
+      endpoint,
+      body.modelId,
+      session.id,
+      contextLength,
+      session.workingDir
+    );
     if (!applied) {
       return createErrorResponse(ApiErrorCode.OPERATION_FAILED, `${session.mode} has no known custom-model mechanism`);
     }
@@ -3643,7 +3650,8 @@ export function registerSessionRoutes(
         cmEndpoint,
         customModel.modelId,
         qsCustomModelSessionId,
-        cmContextLength
+        cmContextLength,
+        resolvedCasePath
       );
       if (!cmApplied) {
         return createErrorResponse(ApiErrorCode.OPERATION_FAILED, `${mode} has no known custom-model mechanism`);