fix(web): finish the settings-environment migration

Two consumers were left on the primary environment after the settings
panels moved to the resolved settings environment, so on a hosted session
with no primary device they disagreed with the panels that write them.

- New-thread defaults (`defaultThreadEnvMode`,
  `newWorktreesStartFromOrigin`) read `primaryServerSettingsAtom` in
  `useNewThreadHandler` and `ChatView`, so the General controls saved and
  re-displayed while new drafts kept the schema defaults. Both now read
  `settingsServerSettingsAtom` — the environment those controls write.
- `SourceControlSettingsPanel` still resolved its discovery target and
  gated `SourceControlWritingSettingsSection` on `usePrimaryEnvironment`,
  so the writer-model and fetch-interval controls never mounted there.
  It now uses `useSettingsEnvironmentId`, matching the section's own hooks.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: IAmJSD

apps/web/src/components/ChatView.tsx

@@ -220,8 +220,8 @@ import { useEnvironmentQuery } from "../state/query";
 import {
   primaryServerAvailableEditorsAtom,
   primaryServerKeybindingsAtom,
-  primaryServerSettingsAtom,
   serverEnvironment,
+  settingsServerSettingsAtom,
 } from "../state/server";
 import { terminalEnvironment } from "../state/terminal";
 import { threadEnvironment, useEnvironmentThread } from "../state/threads";
@@ -1261,10 +1261,10 @@ function ChatViewContent(props: ChatViewProps) {
   }, [routeKind, routeThreadRef, routeThreadState]);
   const markThreadVisited = useUiStateStore((store) => store.markThreadVisited);
   const settings = useEnvironmentSettings(environmentId);
-  // New-thread defaults live in the primary environment's settings.json (the
-  // settings UI never writes to remote environments), so read them from the
-  // primary server rather than the thread's environment.
-  const primaryServerSettings = useAtomValue(primaryServerSettingsAtom);
+  // New-thread defaults live in the settings environment's settings.json —
+  // the one the settings UI writes to — so read them from there rather than
+  // from the thread's own environment.
+  const settingsServerSettings = useAtomValue(settingsServerSettingsAtom);
   const setStickyComposerModelSelection = useComposerDraftStore(
     (store) => store.setStickyModelSelection,
   );
@@ -3980,7 +3980,7 @@ function ChatViewContent(props: ChatViewProps) {
     ? (draftThread?.startFromOrigin ?? false)
     : canOverrideServerThreadEnvMode
       ? (pendingServerThreadStartFromOriginByThreadId[activeThread?.id ?? ""] ??
-        primaryServerSettings.newWorktreesStartFromOrigin)
+        settingsServerSettings.newWorktreesStartFromOrigin)
       : false;
   const sendEnvMode = resolveSendEnvMode({
     requestedEnvMode: envMode,
@@ -5816,7 +5816,7 @@ function ChatViewContent(props: ChatViewProps) {
           envMode: mode,
           startFromOrigin: resolveNewDraftStartFromOrigin({
             envMode: mode,
-            newWorktreesStartFromOrigin: primaryServerSettings.newWorktreesStartFromOrigin,
+            newWorktreesStartFromOrigin: settingsServerSettings.newWorktreesStartFromOrigin,
           }),
           ...(mode === "worktree" && draftThread?.worktreePath ? { worktreePath: null } : {}),
         });
@@ -5828,7 +5828,7 @@ function ChatViewContent(props: ChatViewProps) {
       composerDraftTarget,
       draftThread?.worktreePath,
       isLocalDraftThread,
-      primaryServerSettings.newWorktreesStartFromOrigin,
+      settingsServerSettings.newWorktreesStartFromOrigin,
       setPendingServerThreadEnvMode,
       scheduleComposerFocus,
       setDraftThreadContext,

apps/web/src/components/settings/SourceControlSettings.tsx

@@ -19,8 +19,8 @@ import {
 
 import { useGlobalSettings, useUpdateGlobalSettings } from "../../hooks/useSettings";
 import { cn } from "../../lib/utils";
-import { usePrimaryEnvironment } from "../../state/environments";
 import { useEnvironmentQuery } from "../../state/query";
+import { useSettingsEnvironmentId } from "../../state/settingsEnvironment";
 import { sourceControlEnvironment } from "../../state/sourceControl";
 import { Badge } from "../ui/badge";
 import { Button } from "../ui/button";
@@ -508,7 +508,10 @@ function EmptySourceControlDiscovery({
 }
 
 export function SourceControlSettingsPanel() {
-  const environmentId = usePrimaryEnvironment()?.environmentId ?? null;
+  // The same environment the writing settings below read and write, so the
+  // discovery scan and the writer controls agree about which device they
+  // describe — and so both still mount on a session with no primary device.
+  const environmentId = useSettingsEnvironmentId();
   const discovery = useEnvironmentQuery(
     environmentId === null
       ? null

apps/web/src/hooks/useHandleNewThread.ts

@@ -22,19 +22,21 @@ import {
 } from "../logicalProject";
 import { readThreadShell, useProjects, useThread } from "../state/entities";
 import { resolveNewDraftStartFromOrigin } from "../lib/chatThreadActions";
-import { primaryServerSettingsAtom } from "../state/server";
+import { settingsServerSettingsAtom } from "../state/server";
 import { resolveThreadRouteTarget } from "../threadRoutes";
 import { legacyProjectCwdPreferenceKey, useUiStateStore } from "../uiStateStore";
 import { useClientSettings } from "./useSettings";
 
 export function useNewThreadHandler() {
   const projects = useProjects();
   // New-thread defaults are a user preference, and the settings UI only ever
-  // edits the primary environment's settings.json. Reading the target
+  // edits the settings environment's settings.json. Reading the target
   // environment's own settings here would silently reset remote projects to
   // the decoded defaults ("local" mode, current branch), since nothing can
-  // set those values on a remote server.
-  const primaryServerSettings = useAtomValue(primaryServerSettingsAtom);
+  // set those values on a remote server. This must stay the same environment
+  // the settings panels write to, or the General controls would save and
+  // re-display values that new threads never pick up.
+  const settingsServerSettings = useAtomValue(settingsServerSettingsAtom);
   const projectGroupingSettings = useClientSettings(selectProjectGroupingSettings);
   const router = useRouter();
   const getCurrentRouteTarget = useCallback(() => {
@@ -146,7 +148,7 @@ export function useNewThreadHandler() {
           // preserved. When the draft is already open and no options were
           // passed, leave it alone entirely — the user may have just picked a
           // branch in the composer.
-          const defaultEnvMode = primaryServerSettings.defaultThreadEnvMode;
+          const defaultEnvMode = settingsServerSettings.defaultThreadEnvMode;
           const workspaceContext = hasExplicitWorkspaceOption
             ? {
                 ...(hasBranchOption ? { branch: options?.branch ?? null } : {}),
@@ -162,7 +164,7 @@ export function useNewThreadHandler() {
                   envMode: defaultEnvMode,
                   startFromOrigin: resolveNewDraftStartFromOrigin({
                     envMode: defaultEnvMode,
-                    newWorktreesStartFromOrigin: primaryServerSettings.newWorktreesStartFromOrigin,
+                    newWorktreesStartFromOrigin: settingsServerSettings.newWorktreesStartFromOrigin,
                   }),
                 };
           if (workspaceContext) {
@@ -244,7 +246,7 @@ export function useNewThreadHandler() {
       const draftId = newDraftId();
       const threadId = newThreadId();
       const createdAt = new Date().toISOString();
-      const initialEnvMode = options?.envMode ?? primaryServerSettings.defaultThreadEnvMode;
+      const initialEnvMode = options?.envMode ?? settingsServerSettings.defaultThreadEnvMode;
       return (async () => {
         setLogicalProjectDraftThreadId(logicalProjectKey, projectRef, draftId, {
           threadId,
@@ -256,7 +258,7 @@ export function useNewThreadHandler() {
             options?.startFromOrigin ??
             resolveNewDraftStartFromOrigin({
               envMode: initialEnvMode,
-              newWorktreesStartFromOrigin: primaryServerSettings.newWorktreesStartFromOrigin,
+              newWorktreesStartFromOrigin: settingsServerSettings.newWorktreesStartFromOrigin,
             }),
           runtimeMode: carryRuntimeMode ?? DEFAULT_RUNTIME_MODE,
           ...(carryInteractionMode ? { interactionMode: carryInteractionMode } : {}),
@@ -278,7 +280,7 @@ export function useNewThreadHandler() {
         });
       })();
     },
-    [getCurrentRouteTarget, primaryServerSettings, projectGroupingSettings, projects, router],
+    [getCurrentRouteTarget, settingsServerSettings, projectGroupingSettings, projects, router],
   );
 }