refactor: move model picker to Settings and fix runtime validation

Move the commit-message model dropdown from the git diff panel to
Settings > Git. Source the model list from the existing codex-section
fetch to avoid duplicate getModelList fan-out.

Replace the old normalize-and-persist hook with a pure runtime guard
(effectiveCommitMessageModelId) that validates the saved preference
against the active workspace's models without overwriting the persisted
setting — so switching workspaces no longer silently clears the choice.

Author: joshhbk

src-tauri/src/bin/codex_monitor_daemon.rs

@@ -1216,14 +1216,10 @@ impl DaemonState {
         )
         .await?;
         let diff = git_ui_core::collect_workspace_diff_core(&repo_root)?;
-        let (commit_message_prompt, default_commit_message_model_id) = {
+        let commit_message_prompt = {
             let settings = self.app_settings.lock().await;
-            (
-                settings.commit_message_prompt.clone(),
-                settings.commit_message_model_id.clone(),
-            )
+            settings.commit_message_prompt.clone()
         };
-        let commit_message_model_id = commit_message_model_id.or(default_commit_message_model_id);
         codex_aux_core::generate_commit_message_core(
             &self.sessions,
             workspace_id,

src-tauri/src/codex/mod.rs

@@ -880,12 +880,6 @@ pub(crate) async fn generate_commit_message(
     app: AppHandle,
 ) -> Result<String, String> {
     if remote_backend::is_remote_mode(&*state).await {
-        let commit_message_model_id = if commit_message_model_id.is_some() {
-            commit_message_model_id
-        } else {
-            let settings = state.app_settings.lock().await;
-            settings.commit_message_model_id.clone()
-        };
         let value = remote_backend::call_remote(
             &*state,
             app,
@@ -901,14 +895,10 @@ pub(crate) async fn generate_commit_message(
 
     let diff = crate::git::get_workspace_diff(&workspace_id, &state).await?;
 
-    let (commit_message_prompt, default_commit_message_model_id) = {
+    let commit_message_prompt = {
         let settings = state.app_settings.lock().await;
-        (
-            settings.commit_message_prompt.clone(),
-            settings.commit_message_model_id.clone(),
-        )
+        settings.commit_message_prompt.clone()
     };
-    let commit_message_model_id = commit_message_model_id.or(default_commit_message_model_id);
     crate::shared::codex_aux_core::generate_commit_message_core(
         &state.sessions,
         workspace_id,

src-tauri/src/shared/codex_aux_core.rs

@@ -616,6 +616,7 @@ where
         sessions,
         workspace_id,
         prompt,
+        None,
         on_hide_thread,
         "Timeout waiting for agent configuration generation",
         "Unknown error during agent configuration generation",

src/App.tsx

@@ -107,7 +107,7 @@ import { useWorkspaceLaunchScript } from "@app/hooks/useWorkspaceLaunchScript";
 import { useWorkspaceLaunchScripts } from "@app/hooks/useWorkspaceLaunchScripts";
 import { useWorktreeSetupScript } from "@app/hooks/useWorktreeSetupScript";
 import { useGitCommitController } from "@app/hooks/useGitCommitController";
-import { useCommitMessageModelSelection } from "@app/hooks/useCommitMessageModelSelection";
+import { effectiveCommitMessageModelId } from "@/features/git/utils/commitMessageModelSelection";
 import { WorkspaceHome } from "@/features/workspaces/components/WorkspaceHome";
 import { MobileServerSetupWizard } from "@/features/mobile/components/MobileServerSetupWizard";
 import { useMobileServerSetup } from "@/features/mobile/hooks/useMobileServerSetup";
@@ -429,15 +429,10 @@ function MainApp() {
     setAccessMode,
     persistThreadCodexParams,
   });
-  const {
-    resolvedCommitMessageModelId,
-    onCommitMessageModelChange,
-  } = useCommitMessageModelSelection({
-    models,
-    commitMessageModelId: appSettings.commitMessageModelId,
-    setAppSettings,
-    queueSaveSettings,
-  });
+  const commitMessageModelId = useMemo(
+    () => effectiveCommitMessageModelId(models, appSettings.commitMessageModelId),
+    [models, appSettings.commitMessageModelId],
+  );
 
   const composerShortcuts = {
     modelShortcut: appSettings.composerModelShortcut,
@@ -1458,7 +1453,7 @@ function MainApp() {
     activeWorkspace,
     activeWorkspaceId,
     activeWorkspaceIdRef,
-    commitMessageModelId: resolvedCommitMessageModelId,
+    commitMessageModelId,
     gitStatus,
     refreshGitStatus,
     refreshGitLog,
@@ -2197,8 +2192,6 @@ function MainApp() {
     commitMessageError,
     onCommitMessageChange: handleCommitMessageChange,
     onGenerateCommitMessage: handleGenerateCommitMessage,
-    commitMessageModelId: resolvedCommitMessageModelId,
-    onCommitMessageModelChange,
     onCommit: handleCommit,
     onCommitAndPush: handleCommitAndPush,
     onCommitAndSync: handleCommitAndSync,

src/features/app/hooks/useCommitMessageModelSelection.ts

@@ -1,4 +1,4 @@
-import type { GitHubIssue, GitHubPullRequest, GitLogEntry, ModelOption } from "../../../types";
+import type { GitHubIssue, GitHubPullRequest, GitLogEntry } from "../../../types";
 import type { MouseEvent as ReactMouseEvent } from "react";
 import { Menu, MenuItem } from "@tauri-apps/api/menu";
 import { LogicalPosition } from "@tauri-apps/api/dpi";
@@ -127,9 +127,6 @@ type GitDiffPanelProps = {
   commitMessageError?: string | null;
   onCommitMessageChange?: (value: string) => void;
   onGenerateCommitMessage?: () => void | Promise<void>;
-  models?: ModelOption[];
-  commitMessageModelId?: string | null;
-  onCommitMessageModelChange?: (id: string | null) => void;
   // Git operations
   onCommit?: () => void | Promise<void>;
   onCommitAndPush?: () => void | Promise<void>;
@@ -219,9 +216,6 @@ export function GitDiffPanel({
   commitMessageError = null,
   onCommitMessageChange,
   onGenerateCommitMessage,
-  models = [],
-  commitMessageModelId = null,
-  onCommitMessageModelChange,
   onCommit,
   onCommitAndPush: _onCommitAndPush,
   onCommitAndSync: _onCommitAndSync,
@@ -736,9 +730,6 @@ export function GitDiffPanel({
           commitMessageLoading={commitMessageLoading}
           canGenerateCommitMessage={canGenerateCommitMessage}
           onGenerateCommitMessage={onGenerateCommitMessage}
-          models={models}
-          commitMessageModelId={commitMessageModelId}
-          onCommitMessageModelChange={onCommitMessageModelChange}
           stagedFiles={stagedFiles}
           unstagedFiles={unstagedFiles}
           commitLoading={commitLoading}

src/features/git/components/GitDiffPanel.tsx

@@ -1,11 +1,10 @@
-import type { GitHubIssue, GitHubPullRequest, GitLogEntry, ModelOption } from "../../../types";
+import type { GitHubIssue, GitHubPullRequest, GitLogEntry } from "../../../types";
 import type { MouseEvent as ReactMouseEvent } from "react";
-import { useCallback, useEffect, useRef, useState } from "react";
+import { useCallback, useEffect, useState } from "react";
 import { openUrl } from "@tauri-apps/plugin-opener";
 import ArrowLeftRight from "lucide-react/dist/esm/icons/arrow-left-right";
 import ChevronDown from "lucide-react/dist/esm/icons/chevron-down";
 import ChevronRight from "lucide-react/dist/esm/icons/chevron-right";
-import Cpu from "lucide-react/dist/esm/icons/cpu";
 import Download from "lucide-react/dist/esm/icons/download";
 import RotateCcw from "lucide-react/dist/esm/icons/rotate-ccw";
 import RotateCw from "lucide-react/dist/esm/icons/rotate-cw";
@@ -15,11 +14,6 @@ import {
   MagicSparkleIcon,
   MagicSparkleLoaderIcon,
 } from "@/features/shared/components/MagicSparkleIcon";
-import {
-  PopoverMenuItem,
-  PopoverSurface,
-} from "../../design-system/components/popover/PopoverPrimitives";
-import { useDismissibleMenu } from "../../app/hooks/useDismissibleMenu";
 import type { GitPanelMode } from "../types";
 import type { PerFileDiffGroup } from "../utils/perFileThreadDiffs";
 import {
@@ -330,9 +324,6 @@ type GitDiffModeContentProps = {
     commitMessageLoading: boolean;
     canGenerateCommitMessage: boolean;
     onGenerateCommitMessage?: () => void | Promise<void>;
-    models: ModelOption[];
-    commitMessageModelId: string | null;
-    onCommitMessageModelChange?: (id: string | null) => void;
     stagedFiles: DiffFile[];
     unstagedFiles: DiffFile[];
     commitLoading: boolean;
@@ -389,9 +380,6 @@ export function GitDiffModeContent({
     commitMessageLoading,
     canGenerateCommitMessage,
     onGenerateCommitMessage,
-    models,
-    commitMessageModelId,
-    onCommitMessageModelChange,
     stagedFiles,
     unstagedFiles,
     commitLoading,
@@ -416,20 +404,6 @@ export function GitDiffModeContent({
     onShowFileMenu,
     onDiffListClick,
 }: GitDiffModeContentProps) {
-    const [commitModelOpen, setCommitModelOpen] = useState(false);
-    const commitModelRef = useRef<HTMLDivElement | null>(null);
-    useDismissibleMenu({
-        isOpen: commitModelOpen,
-        containerRef: commitModelRef,
-        onClose: () => setCommitModelOpen(false),
-    });
-    const selectedCommitModel = commitMessageModelId
-        ? models.find((m) => m.model === commitMessageModelId) ?? null
-        : models.find((m) => m.isDefault) ?? models[0] ?? null;
-    const commitModelLabel = selectedCommitModel?.displayName?.trim()
-        || selectedCommitModel?.model?.trim()
-        || "Model";
-
     const normalizedGitRoot = normalizeRootPath(gitRoot);
     const missingRepo = isMissingRepo(error);
     const gitRootNotFound = isGitRootNotFound(error);
@@ -572,61 +546,6 @@ export function GitDiffModeContent({
                             )}
                         </button>
                     </div>
-                    {models.length > 0 && (
-                        <div className="open-app-menu commit-model-menu" ref={commitModelRef}>
-                            <div className="open-app-button">
-                                <button
-                                    type="button"
-                                    className="ghost open-app-action"
-                                    onClick={() => setCommitModelOpen((prev) => !prev)}
-                                    disabled={commitMessageLoading}
-                                    aria-label="Select model for commit message"
-                                >
-                                    <span className="open-app-label">
-                                        <Cpu size={14} aria-hidden />
-                                        {commitModelLabel}
-                                    </span>
-                                </button>
-                                <button
-                                    type="button"
-                                    className="ghost open-app-toggle"
-                                    onClick={() => setCommitModelOpen((prev) => !prev)}
-                                    disabled={commitMessageLoading}
-                                    aria-haspopup="menu"
-                                    aria-expanded={commitModelOpen}
-                                    aria-label="Toggle model menu"
-                                >
-                                    <ChevronDown size={14} aria-hidden />
-                                </button>
-                            </div>
-                            {commitModelOpen && (
-                                <PopoverSurface
-                                    className="open-app-dropdown commit-model-dropdown"
-                                    role="menu"
-                                >
-                                    {models.map((m) => {
-                                        const isActive = commitMessageModelId
-                                            ? m.model === commitMessageModelId
-                                            : m === selectedCommitModel;
-                                        return (
-                                            <PopoverMenuItem
-                                                key={m.id}
-                                                className="open-app-option"
-                                                onClick={() => {
-                                                    onCommitMessageModelChange?.(m.model);
-                                                    setCommitModelOpen(false);
-                                                }}
-                                                icon={<Cpu size={14} aria-hidden />}
-                                                active={isActive}
-                                            >
-                                                {m.displayName?.trim() || m.model}
-                                            </PopoverMenuItem>
-                                        );
-                                    })}
-                                </PopoverSurface>
-                            )}
-                        </div>
-                    )}
                     <CommitButton
                         commitMessage={commitMessage}
                         hasStagedFiles={stagedFiles.length > 0}

src/features/git/components/GitDiffPanelModeContent.tsx

@@ -1,6 +1,6 @@
 import { describe, expect, it } from "vitest";
 import type { ModelOption } from "@/types";
-import { resolveCommitMessageModelSelection } from "./commitMessageModelSelection";
+import { effectiveCommitMessageModelId } from "./commitMessageModelSelection";
 
 const MODELS: ModelOption[] = [
   {
@@ -23,45 +23,20 @@ const MODELS: ModelOption[] = [
   },
 ];
 
-describe("resolveCommitMessageModelSelection", () => {
-  it("keeps null selection unchanged", () => {
-    expect(resolveCommitMessageModelSelection(MODELS, null)).toEqual({
-      resolvedModelId: null,
-      normalizedModelId: null,
-      shouldNormalize: false,
-    });
+describe("effectiveCommitMessageModelId", () => {
+  it("passes through null when no model is saved", () => {
+    expect(effectiveCommitMessageModelId(MODELS, null)).toBeNull();
   });
 
-  it("keeps explicit selection when it still exists", () => {
-    expect(resolveCommitMessageModelSelection(MODELS, "gpt-5.1")).toEqual({
-      resolvedModelId: "gpt-5.1",
-      normalizedModelId: "gpt-5.1",
-      shouldNormalize: false,
-    });
+  it("returns the saved model when it exists in the workspace", () => {
+    expect(effectiveCommitMessageModelId(MODELS, "gpt-5.1")).toBe("gpt-5.1");
   });
 
-  it("falls back to the default model when selected model disappears", () => {
-    expect(resolveCommitMessageModelSelection(MODELS, "gpt-4.1")).toEqual({
-      resolvedModelId: "gpt-5.2",
-      normalizedModelId: "gpt-5.2",
-      shouldNormalize: true,
-    });
+  it("falls back to null when saved model is unavailable in the workspace", () => {
+    expect(effectiveCommitMessageModelId(MODELS, "gpt-4.1")).toBeNull();
   });
 
-  it("falls back to first model when no default exists", () => {
-    const noDefault = MODELS.map((model) => ({ ...model, isDefault: false }));
-    expect(resolveCommitMessageModelSelection(noDefault, "gpt-4.1")).toEqual({
-      resolvedModelId: "gpt-5.1",
-      normalizedModelId: "gpt-5.1",
-      shouldNormalize: true,
-    });
-  });
-
-  it("normalizes to null when no models are available", () => {
-    expect(resolveCommitMessageModelSelection([], "gpt-4.1")).toEqual({
-      resolvedModelId: null,
-      normalizedModelId: null,
-      shouldNormalize: true,
-    });
+  it("falls back to null when no models are available", () => {
+    expect(effectiveCommitMessageModelId([], "gpt-5.1")).toBeNull();
   });
 });