fix(model): migrate retired claude-sonnet-4-7 default instead of pinning dead model

claude-sonnet-4-7 was retired from the Anthropic API but remains the
default model hardcoded in both the webview (DEFAULT_CLAUDE_MODEL_ID,
default props) and the Java side (SessionState, HandlerContext,
ChatWindowDelegate, ClaudePricingTable). Every flow that falls back to
the default - or restores a persisted tab that had Sonnet 4.7 selected -
now fails on every send:

  There is an issue with the selected model (claude-sonnet-4-7[1m]).
  It may not exist or you may not have access to it.

LEGACY_CLAUDE_MODEL_ID_ALIASES also mapped sonnet-4-6 -> sonnet-4-7,
i.e. one retired id to another retired id, so normalizeClaudeModelId()
kept returning a dead id (#1678).

Webview:
- DEFAULT_CLAUDE_MODEL_ID: sonnet-4-7 -> sonnet-5 (same-tier successor)
- legacy aliases now map every retired id to a live model:
  sonnet-4-6/sonnet-4-7 -> sonnet-5, opus-4-6 -> opus-4-8
- remove claude-sonnet-4-7 from CLAUDE_MODELS and sonnet47 i18n entries;
  move the "Use the default model" description to Sonnet 5 (all locales)
- default selectedModel props use DEFAULT_CLAUDE_MODEL_ID instead of
  duplicated literals

Java:
- sync all four defaults to claude-sonnet-5
- SessionState.setModel() migrates retired ids on write so restored
  .idea/claudeCodeTabState.xml tabs self-heal instead of spawning a CLI
  pinned to a dead model; [1m] suffix is preserved
- lookup-table entries (pricing/context-limit/effort sets) keep the
  retired ids so historical usage stats keep resolving

Fixes #1678

src/main/java/com/github/claudecodegui/handler/core/HandlerContext.java

@@ -17,7 +17,7 @@ import java.util.function.Supplier;
  */
 public class HandlerContext {
 
-    public static final String DEFAULT_MODEL = "claude-sonnet-4-7";
+    public static final String DEFAULT_MODEL = "claude-sonnet-5";
     public static final String DEFAULT_PROVIDER = "claude";
 
     private final Project project;

src/main/java/com/github/claudecodegui/provider/pricing/ClaudePricingTable.java

@@ -13,7 +13,7 @@ import java.util.Map;
  */
 public final class ClaudePricingTable {
 
-    public static final String DEFAULT_MODEL = "claude-sonnet-4-7";
+    public static final String DEFAULT_MODEL = "claude-sonnet-5";
 
     private static final ClaudePricing DEFAULT_PRICING = new ClaudePricing(3.0, 15.0, 3.75, 0.30);
     private static final ClaudePricing TIERED_SONNET_PRICING = new ClaudePricing(3.0, 15.0, 3.75, 0.30, 6.0, 22.5, 7.5, 0.60);

src/main/java/com/github/claudecodegui/session/SessionState.java

@@ -83,7 +83,7 @@ public class SessionState {
     // explicit, informed opt-in — see security remediation A: shipping bypass as the
     // out-of-the-box default removed the only confirmation gate for AI-issued commands.
     private volatile String permissionMode = "default";
-    private volatile String model = "claude-sonnet-4-7";
+    private volatile String model = "claude-sonnet-5";
     private volatile String provider = "claude";
     // Reasoning effort (thinking depth). Null means "do not override SDK/settings".
     private volatile String reasoningEffort = null;
@@ -213,7 +213,49 @@ public class SessionState {
     }
 
     public void setModel(String model) {
-        this.model = model;
+        this.model = normalizeRetiredModelId(model);
+    }
+
+    /**
+     * Migrate retired Claude model ids to their live replacement on write.
+     *
+     * <p>Persisted tab state (.idea/claudeCodeTabState.xml) and history sessions keep
+     * whatever model id was saved forever. When a model is retired from the API
+     * (sonnet-4-6, sonnet-4-7, ...), restoring such a tab would otherwise spawn a CLI
+     * pinned to a dead model that fails on every send ("It may not exist or you may
+     * not have access to it") - see #1678. Migrating here self-heals restored tabs
+     * without touching the persisted XML.</p>
+     *
+     * @param model raw model id (may be null, blank, carry a [1m] suffix, or be retired)
+     * @return the model id to store - retired ids mapped to their live replacement,
+     *         anything else (including non-Claude ids) passed through unchanged
+     */
+    static String normalizeRetiredModelId(String model) {
+        if (model == null) {
+            return null;
+        }
+        String trimmed = model.trim();
+        if (trimmed.isEmpty()) {
+            return model;
+        }
+        String base = trimmed;
+        boolean oneM = false;
+        if (base.endsWith("[1m]")) {
+            base = base.substring(0, base.length() - "[1m]".length());
+            oneM = true;
+        }
+        switch (base) {
+            case "claude-sonnet-4-6":
+            case "claude-sonnet-4-7":
+                base = "claude-sonnet-5";
+                break;
+            case "claude-opus-4-6":
+                base = "claude-opus-4-8";
+                break;
+            default:
+                return trimmed;
+        }
+        return oneM ? base + "[1m]" : base;
     }
 
     public void setProvider(String provider) {

src/main/java/com/github/claudecodegui/ui/ChatWindowDelegate.java

@@ -440,7 +440,7 @@ public class ChatWindowDelegate {
             String mode = session != null ? session.getPermissionMode() : "default";
             com.github.claudecodegui.notifications.ClaudeNotifier.setMode(project, mode);
 
-            String model = session != null ? session.getModel() : "claude-sonnet-4-7";
+            String model = session != null ? session.getModel() : "claude-sonnet-5";
             com.github.claudecodegui.notifications.ClaudeNotifier.setModel(project, model);
 
             try {

src/test/java/com/github/claudecodegui/session/SessionStateTest.java

@@ -0,0 +1,75 @@
+package com.github.claudecodegui.session;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Regression tests for retired Claude model id migration on session state writes
+ * (persisted tab / history restore self-heal) - see #1678.
+ */
+public class SessionStateTest {
+
+    @Test
+    public void setModelMigratesRetiredSonnet47ToSonnet5() {
+        SessionState state = new SessionState();
+        // Saved by versions <= 0.5.2 where sonnet-4-7 was the default model.
+        state.setModel("claude-sonnet-4-7");
+        Assert.assertEquals("claude-sonnet-5", state.getModel());
+    }
+
+    @Test
+    public void setModelMigratesRetiredSonnet46ToSonnet5() {
+        SessionState state = new SessionState();
+        state.setModel("claude-sonnet-4-6");
+        Assert.assertEquals("claude-sonnet-5", state.getModel());
+    }
+
+    @Test
+    public void setModelMigratesRetiredOpus46ToOpus48() {
+        SessionState state = new SessionState();
+        state.setModel("claude-opus-4-6");
+        Assert.assertEquals("claude-opus-4-8", state.getModel());
+    }
+
+    @Test
+    public void setModelPreserves1MSuffixWhenMigrating() {
+        SessionState state = new SessionState();
+        state.setModel("claude-sonnet-4-7[1m]");
+        Assert.assertEquals("claude-sonnet-5[1m]", state.getModel());
+    }
+
+    @Test
+    public void setModelLeavesLiveModelsUntouched() {
+        SessionState state = new SessionState();
+        state.setModel("claude-sonnet-5");
+        Assert.assertEquals("claude-sonnet-5", state.getModel());
+        state.setModel("claude-opus-4-8[1m]");
+        Assert.assertEquals("claude-opus-4-8[1m]", state.getModel());
+    }
+
+    @Test
+    public void setModelLeavesNonClaudeAndUnknownIdsUntouched() {
+        SessionState state = new SessionState();
+        // Non-Claude provider models must pass through unchanged.
+        state.setModel("gpt-5.6-sol");
+        Assert.assertEquals("gpt-5.6-sol", state.getModel());
+        state.setModel("qwen3.5-plus");
+        Assert.assertEquals("qwen3.5-plus", state.getModel());
+    }
+
+    @Test
+    public void setModelHandlesNullAndBlank() {
+        SessionState state = new SessionState();
+        state.setModel(null);
+        Assert.assertNull(state.getModel());
+        state.setModel("  ");
+        Assert.assertEquals("  ", state.getModel());
+    }
+
+    @Test
+    public void defaultModelIsTheLiveSonnet5() {
+        SessionState state = new SessionState();
+        // The initial value must never be a retired id (#1678).
+        Assert.assertEquals("claude-sonnet-5", state.getModel());
+    }
+}

webview/src/components/ChatInputBox/ButtonArea.tsx

@@ -1,6 +1,7 @@
 import { useCallback, useMemo, useState, useEffect, useRef } from 'react';
 import { useTranslation } from 'react-i18next';
 import type { ButtonAreaProps, CodexFastMode, ModelInfo, PermissionMode, ReasoningEffort } from './types';
+import { DEFAULT_CLAUDE_MODEL_ID } from './types';
 import { CodexFastModeSelect, ConfigSelect, ModelSelect, ModeSelect, ProviderSelect, ReasoningSelect } from './selectors';
 import { STORAGE_KEYS, validateCodexCustomModels } from '../../types/provider';
 import type { CodexCustomModel } from '../../types/provider';
@@ -73,7 +74,7 @@ export const ButtonArea = ({
   hasInputContent = false,
   isLoading = false,
   isEnhancing = false,
-  selectedModel = 'claude-sonnet-4-7',
+  selectedModel = DEFAULT_CLAUDE_MODEL_ID,
   permissionMode = 'default',
   currentProvider = 'claude',
   reasoningEffort = 'high',

webview/src/components/ChatInputBox/ChatInputBox.tsx

@@ -14,6 +14,7 @@ import type {
   ChatInputBoxProps,
   PermissionMode,
 } from './types.js';
+import { DEFAULT_CLAUDE_MODEL_ID } from './types.js';
 import { ChatInputBoxHeader } from './ChatInputBoxHeader.js';
 import { ChatInputBoxFooter } from './ChatInputBoxFooter.js';
 import { ResizeHandles } from './ResizeHandles.js';
@@ -76,7 +77,7 @@ export const ChatInputBox = memo(forwardRef<ChatInputBoxHandle, ChatInputBoxProp
   (
     {
       isLoading = false,
-      selectedModel = 'claude-sonnet-4-7',
+      selectedModel = DEFAULT_CLAUDE_MODEL_ID,
       permissionMode = 'default',
       currentProvider = 'claude',
       usagePercentage = 0,

webview/src/components/ChatInputBox/selectors/ModelSelect.test.tsx

@@ -83,13 +83,13 @@ describe('ModelSelect', () => {
       'claude-opus-5',
       'claude-opus-4-8',
       'claude-sonnet-5',
-      'claude-sonnet-4-7',
       'claude-haiku-4-5',
     ]);
     const ids = CLAUDE_MODELS.map((model) => model.id);
     expect(ids).not.toContain('claude-opus-4-7');
     expect(ids).not.toContain('claude-opus-4-6');
     expect(ids).not.toContain('claude-sonnet-4-6');
+    expect(ids).not.toContain('claude-sonnet-4-7');
     expect(ids.some((id) => id.endsWith('[1m]'))).toBe(false);
   });
 

webview/src/components/ChatInputBox/selectors/ModelSelect.tsx

@@ -69,7 +69,6 @@ const DEFAULT_MODEL_MAP: Record<string, ModelInfo> = AVAILABLE_MODELS.reduce(
 const MODEL_LABEL_KEYS: Record<string, string> = {
   'claude-opus-5': 'models.claude.opus5.label',
   'claude-sonnet-5': 'models.claude.sonnet5.label',
-  'claude-sonnet-4-7': 'models.claude.sonnet47.label',
   'claude-sonnet-4-6': 'models.claude.sonnet46.label',
   'claude-fable-5': 'models.claude.fable5.label',
   'claude-opus-4-8': 'models.claude.opus48.label',
@@ -89,7 +88,6 @@ const MODEL_LABEL_KEYS: Record<string, string> = {
 const MODEL_DESCRIPTION_KEYS: Record<string, string> = {
   'claude-opus-5': 'models.claude.opus5.description',
   'claude-sonnet-5': 'models.claude.sonnet5.description',
-  'claude-sonnet-4-7': 'models.claude.sonnet47.description',
   'claude-sonnet-4-6': 'models.claude.sonnet46.description',
   'claude-fable-5': 'models.claude.fable5.description',
   'claude-opus-4-8': 'models.claude.opus48.description',

webview/src/components/ChatInputBox/types.test.ts

@@ -20,7 +20,12 @@ describe('normalizeClaudeModelId', () => {
 
   it('migrates retired Sonnet 4.6 to the current default', () => {
     // Saved by versions <= 0.4.7 where sonnet-4-6 was the default model.
-    expect(normalizeClaudeModelId('claude-sonnet-4-6')).toBe('claude-sonnet-4-7');
+    expect(normalizeClaudeModelId('claude-sonnet-4-6')).toBe('claude-sonnet-5');
+  });
+
+  it('migrates retired Sonnet 4.7 to the current default', () => {
+    // Saved by versions <= 0.5.2 where sonnet-4-7 was the default model (#1678).
+    expect(normalizeClaudeModelId('claude-sonnet-4-7')).toBe('claude-sonnet-5');
   });
 
   it('migrates retired Opus 4.6 to Opus 4.8', () => {
@@ -28,7 +33,8 @@ describe('normalizeClaudeModelId', () => {
   });
 
   it('migrates retired IDs carrying a [1m] suffix', () => {
-    expect(normalizeClaudeModelId('claude-sonnet-4-6[1m]')).toBe('claude-sonnet-4-7');
+    expect(normalizeClaudeModelId('claude-sonnet-4-6[1m]')).toBe('claude-sonnet-5');
+    expect(normalizeClaudeModelId('claude-sonnet-4-7[1m]')).toBe('claude-sonnet-5');
     expect(normalizeClaudeModelId('claude-opus-4-6[1m]')).toBe('claude-opus-4-8');
   });
 

webview/src/components/ChatInputBox/types.ts

@@ -301,15 +301,18 @@ export function strip1MContextSuffix(modelId: string | undefined | null): string
  * CLAUDE_MODELS[0], which is the newest tier and the most likely to be missing
  * from a user's API relay.
  */
-export const DEFAULT_CLAUDE_MODEL_ID = 'claude-sonnet-4-7';
+export const DEFAULT_CLAUDE_MODEL_ID = 'claude-sonnet-5';
 
 /**
- * Retired model IDs → their current-generation replacement. Lookup happens after
+ * Retired model IDs -> their current-generation replacement. Lookup happens after
  * the [1m] suffix is stripped, so keys must be base IDs. Without an entry here a
  * saved retired model fails validation and silently resets to the fallback.
+ * Retired ids must always map to a LIVE model - mapping one retired id to another
+ * (sonnet-4-6 -> sonnet-4-7) kept restoring tabs pinned to a dead model (#1678).
  */
 const LEGACY_CLAUDE_MODEL_ID_ALIASES: Record<string, string> = {
-  'claude-sonnet-4-6': 'claude-sonnet-4-7',
+  'claude-sonnet-4-6': 'claude-sonnet-5',
+  'claude-sonnet-4-7': 'claude-sonnet-5',
   'claude-opus-4-6': 'claude-opus-4-8',
 };
 
@@ -345,12 +348,7 @@ export const CLAUDE_MODELS: ModelInfo[] = [
   {
     id: 'claude-sonnet-5',
     label: 'Sonnet 5',
-    description: 'Sonnet 5 · Upgraded Sonnet model',
-  },
-  {
-    id: 'claude-sonnet-4-7',
-    label: 'Sonnet 4.7',
-    description: 'Sonnet 4.7 · Use the default model',
+    description: 'Sonnet 5 · Use the default model',
   },
   {
     id: 'claude-haiku-4-5',

webview/src/hooks/providers/useModelStatePersistence.test.ts

@@ -207,9 +207,9 @@ describe('useModelStatePersistence — retired model migration', () => {
     renderHook(() => useModelStatePersistence(makeOptions({ setSelectedClaudeModel })));
     vi.advanceTimersByTime(200);
 
-    expect(setSelectedClaudeModel).toHaveBeenCalledWith('claude-sonnet-4-7');
+    expect(setSelectedClaudeModel).toHaveBeenCalledWith('claude-sonnet-5');
     expect(setSelectedClaudeModel).not.toHaveBeenCalledWith('claude-fable-5');
-    expect(bridgeEventsFor('set_model')).toEqual([['set_model', 'claude-sonnet-4-7']]);
+    expect(bridgeEventsFor('set_model')).toEqual([['set_model', 'claude-sonnet-5']]);
   });
 
   it('migrates a backend-supplied retired model via __INITIAL_TAB_MODEL__', () => {
@@ -225,8 +225,8 @@ describe('useModelStatePersistence — retired model migration', () => {
     renderHook(() => useModelStatePersistence(makeOptions({ setSelectedClaudeModel })));
     vi.advanceTimersByTime(200);
 
-    expect(setSelectedClaudeModel).toHaveBeenCalledWith('claude-sonnet-4-7');
-    expect(bridgeEventsFor('set_model')).toEqual([['set_model', 'claude-sonnet-4-7']]);
+    expect(setSelectedClaudeModel).toHaveBeenCalledWith('claude-sonnet-5');
+    expect(bridgeEventsFor('set_model')).toEqual([['set_model', 'claude-sonnet-5']]);
   });
 
   it('falls back to the default model (not the list head) for unrecognized saved models', () => {

webview/src/i18n/locales/en.json

@@ -1915,11 +1915,7 @@
       },
       "sonnet5": {
         "label": "Sonnet 5",
-        "description": "Sonnet 5 · Upgraded Sonnet model"
-      },
-      "sonnet47": {
-        "label": "Sonnet 4.7",
-        "description": "Sonnet 4.7 · Use the default model"
+        "description": "Sonnet 5 · Use the default model"
       },
       "opus5": {
         "label": "Opus 5",

webview/src/i18n/locales/es.json

@@ -1539,11 +1539,7 @@
       },
       "sonnet5": {
         "label": "Sonnet 5",
-        "description": "Sonnet 5 · Modelo mejorado de Sonnet 4.6"
-      },
-      "sonnet47": {
-        "label": "Sonnet 4.7",
-        "description": "Sonnet 4.7 · Modelo recomendado por defecto"
+        "description": "Sonnet 5 · Modelo recomendado por defecto"
       },
       "opus5": {
         "label": "Opus 5",

webview/src/i18n/locales/fr.json

@@ -1539,11 +1539,7 @@
       },
       "sonnet5": {
         "label": "Sonnet 5",
-        "description": "Sonnet 5 · Modèle amélioré de Sonnet 4.6"
-      },
-      "sonnet47": {
-        "label": "Sonnet 4.7",
-        "description": "Sonnet 4.7 · Modèle recommandé par défaut"
+        "description": "Sonnet 5 · Modèle recommandé par défaut"
       },
       "opus5": {
         "label": "Opus 5",

webview/src/i18n/locales/hi.json

@@ -1538,11 +1538,7 @@
       },
       "sonnet5": {
         "label": "Sonnet 5",
-        "description": "Sonnet 5 · Sonnet 4.6 का अपग्रेड मॉडल"
-      },
-      "sonnet47": {
-        "label": "Sonnet 4.7",
-        "description": "Sonnet 4.7 · डिफ़ॉल्ट अनुशंसित मॉडल"
+        "description": "Sonnet 5 · डिफ़ॉल्ट अनुशंसित मॉडल"
       },
       "opus5": {
         "label": "Opus 5",

webview/src/i18n/locales/ja.json

@@ -1550,11 +1550,7 @@
       },
       "sonnet5": {
         "label": "Sonnet 5",
-        "description": "Sonnet 5 · Sonnet 4.6 のアップグレードモデル"
-      },
-      "sonnet47": {
-        "label": "Sonnet 4.7",
-        "description": "Sonnet 4.7 · デフォルトモデルを使用"
+        "description": "Sonnet 5 · デフォルトモデルを使用"
       },
       "opus5": {
         "label": "Opus 5",

webview/src/i18n/locales/ko.json

@@ -1634,11 +1634,7 @@
       },
       "sonnet5": {
         "label": "Sonnet 5",
-        "description": "Sonnet 5 · Sonnet 4.6 업그레이드 모델"
-      },
-      "sonnet47": {
-        "label": "Sonnet 4.7",
-        "description": "Sonnet 4.7 · 기본 모델 사용"
+        "description": "Sonnet 5 · 기본 모델 사용"
       },
       "opus5": {
         "label": "Opus 5",

webview/src/i18n/locales/pt-BR.json

@@ -1689,11 +1689,7 @@
       },
       "sonnet5": {
         "label": "Sonnet 5",
-        "description": "Sonnet 5 · Modelo aprimorado do Sonnet 4.6"
-      },
-      "sonnet47": {
-        "label": "Sonnet 4.7",
-        "description": "Sonnet 4.7 · Usar o modelo padrão"
+        "description": "Sonnet 5 · Usar o modelo padrão"
       },
       "opus5": {
         "label": "Opus 5",

webview/src/i18n/locales/ru.json

@@ -1565,11 +1565,7 @@
       },
       "sonnet5": {
         "label": "Sonnet 5",
-        "description": "Sonnet 5 · Обновленная модель Sonnet 4.6"
-      },
-      "sonnet47": {
-        "label": "Sonnet 4.7",
-        "description": "Sonnet 4.7 · Модель по умолчанию"
+        "description": "Sonnet 5 · Модель по умолчанию"
       },
       "opus5": {
         "label": "Opus 5",

webview/src/i18n/locales/zh-TW.json

@@ -1544,11 +1544,7 @@
       },
       "sonnet5": {
         "label": "Sonnet 5",
-        "description": "Sonnet 5 · Sonnet 4.6 升級模型"
-      },
-      "sonnet47": {
-        "label": "Sonnet 4.7",
-        "description": "Sonnet 4.7 · 預設推薦模型"
+        "description": "Sonnet 5 · 預設推薦模型"
       },
       "opus5": {
         "label": "Opus 5",

webview/src/i18n/locales/zh.json

@@ -1920,11 +1920,7 @@
       },
       "sonnet5": {
         "label": "Sonnet 5",
-        "description": "Sonnet 5 · Sonnet 4.6 升级模型"
-      },
-      "sonnet47": {
-        "label": "Sonnet 4.7",
-        "description": "Sonnet 4.7 · 默认推荐模型"
+        "description": "Sonnet 5 · 默认推荐模型"
       },
       "opus5": {
         "label": "Opus 5",