fix(cliproxy): close second-round review gaps in pool onboarding and remote env

- create-command: show the pool onboarding hint only after profile
  creation fully succeeds; the pre-create placement burned the
  once-per-install dismissal when creation failed or rolled back
- remote env (claude): skip the read-level stale-pin filter once the
  migration marker exists - a post-migration pin is user-intentional
  (e.g. an explicit --config pick equal to a historical default)
- unified-config loader: document that loadOrCreateUnifiedConfig never
  writes to disk, so read paths on legacy installs stay side-effect free

src/auth/commands/create-command.ts

@@ -189,18 +189,6 @@ export async function handleCreate(ctx: CommandContext, args: string[]): Promise
     }
   };
 
-  // Pool suggestion: when creating a 2nd+ native Claude profile, show the
-  // once-per-install onboarding hint.  Print-only, TTY-gated, never blocks.
-  // Pass existingCount + 1 so the hint sees the post-create count (>= 2).
-  // Gated on hasUnifiedConfig() so legacy profiles.json-only installs receive
-  // the hint from ccs doctor only (where dismissal semantics are preserved).
-  if (!profileExistedBeforeCreate && hasUnifiedConfig()) {
-    const existingCount = countNativeClaudeProfiles();
-    if (existingCount >= 1) {
-      maybeShowPoolOnboardingHint(existingCount + 1);
-    }
-  }
-
   try {
     // Create instance directory
     console.log(info(`Creating profile: ${profileName}`));
@@ -326,6 +314,16 @@ export async function handleCreate(ctx: CommandContext, args: string[]): Promise
           )
         );
         console.log('');
+        // Pool suggestion: shown only AFTER the profile creation fully
+        // succeeded (a pre-create hint would burn the once-per-install
+        // dismissal even when creation fails or rolls back).  Print-only,
+        // TTY-gated, never blocks.  Gated on hasUnifiedConfig() so legacy
+        // profiles.json-only installs receive the hint from ccs doctor only
+        // (where dismissal semantics are preserved).  The profile now exists,
+        // so the registry count is already post-create (no +1 needed).
+        if (!profileExistedBeforeCreate && hasUnifiedConfig()) {
+          maybeShowPoolOnboardingHint(countNativeClaudeProfiles());
+        }
         process.exit(0);
       } else {
         await rollbackFailedCreate();

src/cliproxy/__tests__/pool-onboarding-phase5.test.ts

@@ -320,25 +320,23 @@ describe('Phase 5: Pool Onboarding Hint', () => {
   });
 
   // ── 11. Create-command suggestion: hint fires with post-create count ──────
-  it('hint fires with count 2 when create-command passes existingCount+1 for 1 existing profile', async () => {
+  it('hint fires with count 2 after a successful 2nd-profile create (post-create call site)', async () => {
     // NOTE: SIMULATION of the create-command call site, not the real command.
-    // It replicates the threshold logic (existingCount + 1) and calls the same
-    // exported hint symbol; it does not invoke create-command end to end.
-    // 1 existing profile in the registry, simulating pre-create state.
-    // create-command calls maybeShowPoolOnboardingHint(existingCount + 1) = hint(2).
+    // create-command shows the hint only AFTER profile creation succeeds (a
+    // pre-create hint would burn the once-per-install dismissal on a failed
+    // create).  At that point the registry already contains the new profile,
+    // so the call is maybeShowPoolOnboardingHint(countNativeClaudeProfiles()).
     const ccsDir = path.join(tempHome, '.ccs');
-    writeProfiles(ccsDir, ['work']);
+    writeProfiles(ccsDir, ['work', 'personal']); // post-create state: 2 profiles
 
     const consoleSpy = spyOn(console, 'log').mockImplementation(() => {});
     try {
       const { maybeShowPoolOnboardingHint, countNativeClaudeProfiles } = await import(
         `../routing/pool-onboarding-hint?p5create=${Date.now()}`
       );
-      // Replicate the threshold logic from create-command.ts lines 195-200
-      const existingCount = countNativeClaudeProfiles();
-      expect(existingCount).toBe(1);
-      // existingCount >= 1 so the hint is called with existingCount + 1
-      const result = maybeShowPoolOnboardingHint(existingCount + 1);
+      const count = countNativeClaudeProfiles();
+      expect(count).toBe(2);
+      const result = maybeShowPoolOnboardingHint(count);
       expect(result.printed).toBe(true);
       const allOutput = consoleSpy.mock.calls.map((c) => String(c[0])).join('\n');
       expect(allOutput).toContain('2 Claude profiles');

src/cliproxy/config/__tests__/claude-model-neutral.test.ts

@@ -550,4 +550,38 @@ describe('claude provider model-neutral passthrough (Gap 1)', () => {
     // Priority 1 untouched: the explicit pin survives.
     expect(env.ANTHROPIC_MODEL).toBe('claude-sonnet-4-6');
   });
+
+  it('getRemoteEnvVars (claude): migration marker set means pins are user-intentional and NOT filtered', () => {
+    process.env.CCS_HOME = tempHome;
+    const ccsDir = path.join(tempHome, '.ccs');
+    fs.mkdirSync(ccsDir, { recursive: true });
+
+    // Marker present: the file was already cleaned once, so any pin that
+    // exists now was put there deliberately (e.g. ccs claude --config picked
+    // a value that happens to equal a historical default).
+    const markerDir = path.join(ccsDir, 'cliproxy');
+    fs.mkdirSync(markerDir, { recursive: true });
+    fs.writeFileSync(path.join(markerDir, '.claude-model-migrated'), new Date().toISOString());
+
+    const settingsPath = path.join(ccsDir, 'claude.settings.json');
+    fs.writeFileSync(
+      settingsPath,
+      JSON.stringify({
+        env: {
+          ANTHROPIC_BASE_URL: 'http://127.0.0.1:8317/api/provider/claude',
+          ANTHROPIC_AUTH_TOKEN: 'ccs-internal-managed',
+          ANTHROPIC_MODEL: 'claude-sonnet-4-6', // equals a stale default, but post-migration = explicit
+        },
+      }),
+      'utf-8'
+    );
+
+    const env = getRemoteEnvVars('claude', {
+      host: 'example.com',
+      port: 8317,
+      protocol: 'http',
+    });
+
+    expect(env.ANTHROPIC_MODEL).toBe('claude-sonnet-4-6');
+  });
 });

src/cliproxy/config/env-builder.ts

@@ -808,10 +808,14 @@ export function getRemoteEnvVars(
           // never rewrites the file, so a remote-only user whose settings still
           // carry an old auto-written default would stay pinned. Filter stale
           // defaults at read level so values equal to a historical default are
-          // dropped while user-custom pins survive. Priority 1 (explicit custom
-          // settings path) is intentionally left untouched: an explicitly passed
-          // settings file is the user's deliberate choice.
-          if (provider === 'claude') {
+          // dropped while user-custom pins survive. Once the migration marker
+          // exists the file has already been cleaned, so any pin present after
+          // that is user-intentional (e.g. an explicit `ccs claude --config`
+          // pick that happens to equal a historical default) and must NOT be
+          // filtered. Priority 1 (explicit custom settings path) is
+          // intentionally left untouched: an explicitly passed settings file
+          // is the user's deliberate choice.
+          if (provider === 'claude' && !claudeModelMigrationDone()) {
             userEnvVars = filterClaudeStaleModelPins(userEnvVars);
           }
         }

src/config/unified-config-loader.ts

@@ -191,6 +191,9 @@ export function loadUnifiedConfig(): UnifiedConfig | null {
  * Merges with defaults to ensure all sections exist.
  */
 export function loadOrCreateUnifiedConfig(): UnifiedConfig {
+  // Read-only: "create" means an in-memory default object when config.yaml is
+  // absent. This never writes to disk, so callers on legacy installs can use
+  // it for read paths without implicitly creating config.yaml.
   const existing = loadUnifiedConfig();
   if (existing) {
     const merged = mergeWithDefaults(existing);