feat(acp): add unified diff rendering and auth probing

- extract and render ACP content diff blocks and synthesized Cursor edits
- broaden ACP registry auth detection in settings and after installs
- add npx prefetch/probe helpers for registry installs
- cover line diff helpers and ACP transform/registry cases

Author: SDSLeon

src/renderer/components/thread/ChatPane/parts/items/FileChange.tsx

@@ -16,6 +16,7 @@ import {
   extractAcpDiffSummary,
   extractAcpDiffResultPart,
   extractAcpResultPart,
+  readAcpContentEditTexts,
   type ExtractedPart,
 } from "./acpToolPayload";
 import { InlineDiffView } from "./InlineDiffView";
@@ -35,6 +36,7 @@ export const FileChange = memo(function FileChange({ item }: FileChangeProps) {
   const argContent = isCreate ? extractCreateContent(payload) : undefined;
   const diffPart = !isCreate ? extractAcpDiffResultPart(payload) : undefined;
   const diffText = diffPart?.text ? diffPart.text : undefined;
+  const contentEdit = readAcpContentEditTexts(payload);
   const paneActions = useChatPaneActions();
 
   // Some SDKs (e.g. Claude `Write`) don't surface the new file contents on
@@ -108,7 +110,11 @@ export const FileChange = memo(function FileChange({ item }: FileChangeProps) {
       onExpandedChange={setIsExpanded}
     >
       {diffText !== undefined ? (
-        <InlineDiffView diffText={diffText} filePath={payload.path} />
+        <InlineDiffView
+          diffText={diffText}
+          filePath={payload.path}
+          {...(contentEdit ? { oldText: contentEdit.oldText, newText: contentEdit.newText } : {})}
+        />
       ) : argContent !== undefined ? (
         <CommandOutputViewport text={argContent} language={language} />
       ) : fetched.content !== undefined ? (

src/renderer/components/thread/ChatPane/parts/items/InlineDiffView.tsx

@@ -2,6 +2,7 @@ import { Component, useEffect, useState, type ReactNode } from "react";
 import { DiffView, highlighter } from "@git-diff-view/react";
 import type { DiffFile } from "@git-diff-view/react";
 import "@git-diff-view/react/styles/diff-view.css";
+import { normalizeDiffFilePath } from "@/shared/lineUnifiedDiff";
 import {
   buildInWorker,
   diffFileFromBundle,
@@ -18,6 +19,9 @@ const MAX_DIFF_LENGTH = 100_000;
 interface InlineDiffViewProps {
   diffText: string;
   filePath: string;
+  /** When set (Cursor ACP content diffs), passed to git-diff-view for reliable rich rendering. */
+  oldText?: string;
+  newText?: string;
 }
 
 /**
@@ -26,7 +30,8 @@ interface InlineDiffViewProps {
  * keep the UI thread responsive. Falls back to Shiki-highlighted raw diff text
  * when the patch is too large or the worker build fails.
  */
-export function InlineDiffView({ diffText, filePath }: InlineDiffViewProps) {
+export function InlineDiffView({ diffText, filePath, oldText, newText }: InlineDiffViewProps) {
+  const displayPath = normalizeDiffFilePath(filePath);
   const theme = useDiffTheme();
   const [diffFile, setDiffFile] = useState<DiffFile | null>(null);
   const [state, setState] = useState<"building" | "ready" | "fallback">(
@@ -42,10 +47,26 @@ export function InlineDiffView({ diffText, filePath }: InlineDiffViewProps) {
     setState("building");
     setDiffFile(null);
 
-    const { oldName, newName } = extractDiffNames(diffText);
-    const lang = getLang(newName || filePath);
+    const parsedNames = extractDiffNames(diffText);
+    const oldName = parsedNames.oldName || (oldText === "" ? "/dev/null" : `a/${displayPath}`);
+    const newName = parsedNames.newName || `b/${displayPath}`;
+    const lang = getLang(newName || displayPath);
 
-    void buildInWorker([{ key: filePath, diff: diffText, oldName, newName, fileLang: lang }], theme)
+    void buildInWorker(
+      [
+        {
+          key: displayPath,
+          diff: diffText,
+          oldName,
+          newName,
+          fileLang: lang,
+          ...(oldText !== undefined && newText !== undefined
+            ? { oldContent: oldText, newContent: newText }
+            : {}),
+        },
+      ],
+      theme,
+    )
       .then((results) => {
         if (cancelled) return;
         const r = results[0];
@@ -63,7 +84,7 @@ export function InlineDiffView({ diffText, filePath }: InlineDiffViewProps) {
     return () => {
       cancelled = true;
     };
-  }, [diffText, filePath, theme]);
+  }, [diffText, displayPath, oldText, newText, theme]);
 
   if (state === "fallback") {
     return <CommandOutputViewport text={diffText} language="diff" />;

src/renderer/components/thread/ChatPane/parts/items/ToolCallGroup.tsx

@@ -36,6 +36,7 @@ import {
   extractAcpArgsPart,
   extractAcpDiffSummary,
   extractAcpDiffResultPart,
+  readAcpContentEditTexts,
   extractAcpResultPart,
   extractAcpResultText,
   readAcpStringField,
@@ -264,7 +265,13 @@ function ToolCallInline({ item }: { item: RuntimeChatItem }) {
             )
           ) : row.bodyText ? (
             row.bodyKind === "diff" ? (
-              <InlineDiffView diffText={row.bodyText} filePath={row.bodyFilePath ?? ""} />
+              <InlineDiffView
+                diffText={row.bodyText}
+                filePath={row.bodyFilePath ?? ""}
+                {...(row.bodyOldText !== undefined && row.bodyNewText !== undefined
+                  ? { oldText: row.bodyOldText, newText: row.bodyNewText }
+                  : {})}
+              />
             ) : (
               <CommandOutputViewport
                 text={row.bodyText}
@@ -296,6 +303,8 @@ type InlineRow = {
   bodyLanguage?: ViewportLanguage | undefined;
   bodyKind?: "text" | "diff" | undefined;
   bodyFilePath?: string | undefined;
+  bodyOldText?: string | undefined;
+  bodyNewText?: string | undefined;
   /**
    * Absolute path to lazily read from disk when the row is expanded. Set for
    * ACP read tools (e.g. Gemini's `read_file`) that report `locations[]` but
@@ -449,6 +458,7 @@ function getFileChangeRow(item: RuntimeChatItem, isExpanded: boolean): InlineRow
   const createContent = isCreate ? extractCreateContent(payload) : undefined;
   const diffPart = !isCreate ? extractAcpDiffResultPart(payload) : undefined;
   const diffText = diffPart?.text || undefined;
+  const contentEdit = readAcpContentEditTexts(payload);
   const sections: ToolCallSection[] =
     isExpanded &&
     !diffText &&
@@ -488,14 +498,18 @@ function getFileChangeRow(item: RuntimeChatItem, isExpanded: boolean): InlineRow
     rightLabel,
     rightLabelClassName: isError ? "text-danger" : "text-[color:var(--muted)]",
     hasDetails:
-      !!item.streams.file_change_output || createContent !== undefined || hasAuxFields(payload),
+      !!diffText ||
+      !!item.streams.file_change_output ||
+      createContent !== undefined ||
+      hasAuxFields(payload),
     sections,
     bodyText: isExpanded
       ? (diffText ?? createContent ?? item.streams.file_change_output)
       : undefined,
     bodyLanguage: createContent !== undefined ? detectLanguageFromPath(payload.path) : undefined,
     bodyKind: diffText ? "diff" : "text",
     bodyFilePath: payload.path,
+    ...(contentEdit ? { bodyOldText: contentEdit.oldText, bodyNewText: contentEdit.newText } : {}),
   };
 }
 

src/renderer/components/thread/ChatPane/parts/items/acpToolPayload.ts

@@ -11,6 +11,7 @@
  * fields lack extra body details and that's fine.
  */
 
+import { buildLineUnifiedDiff, countLineChangeStats } from "@/shared/lineUnifiedDiff";
 import { detectLanguageFromPath, type ViewportLanguage } from "./languageDetect";
 
 export interface AcpToolResult {
@@ -141,8 +142,28 @@ export function extractAcpArgsPart(payload: unknown): ExtractedPart {
   return { text: safeJson(args), language: "json" };
 }
 
+/** Cursor ACP content-diff blocks stored on the payload by the supervisor mapper. */
+export function readAcpContentEditTexts(
+  payload: unknown,
+): { path: string; oldText: string; newText: string } | undefined {
+  if (!payload || typeof payload !== "object") return undefined;
+  const record = payload as Record<string, unknown>;
+  const path = readPayloadString(payload, "path");
+  const newText = readString(record.editNewText);
+  if (!path || newText === undefined) return undefined;
+  const oldText = readString(record.editOldText) ?? "";
+  return { path, oldText, newText };
+}
+
 /** Return only ACP result bodies that are unified diffs, or synthesize one from edit args. */
 export function extractAcpDiffResultPart(payload: unknown): ExtractedPart {
+  const contentEdit = readAcpContentEditTexts(payload);
+  if (contentEdit) {
+    return {
+      text: buildLineUnifiedDiff(contentEdit.path, contentEdit.oldText, contentEdit.newText),
+      language: "diff",
+    };
+  }
   const resultPart = extractAcpResultPart(payload);
   if (resultPart.language === "diff") return resultPart;
   const synthesized = synthesizeEditDiff(payload);
@@ -179,6 +200,11 @@ export function extractAcpPatchTargetPath(payload: unknown): string | undefined
 }
 
 export function extractAcpDiffSummary(payload: unknown): DiffSummary | undefined {
+  const contentEdit = readAcpContentEditTexts(payload);
+  if (contentEdit) {
+    const stats = countLineChangeStats(contentEdit.oldText, contentEdit.newText);
+    return stats.added === 0 && stats.removed === 0 ? undefined : stats;
+  }
   const changesSummary = summarizeStructuredFileChanges(payload);
   if (changesSummary) return changesSummary;
   const diffPart = extractAcpDiffResultPart(payload);

src/renderer/utils/acpRegistryAuth.ts

@@ -54,6 +54,28 @@ export function findTerminalAuthMethodForStatus(
   return status?.authMethods?.find(isTerminalAuthMethod);
 }
 
+/** First agent-owned auth method advertised by any env for the same install. */
+export function findAgentAuthMethodInStatuses(
+  statuses: readonly AgentStatus[],
+): AgentOwnedAuthMethod | undefined {
+  for (const status of statuses) {
+    const method = status.authMethods?.find(isAgentAuthMethod);
+    if (method) return method;
+  }
+  return undefined;
+}
+
+/** First terminal auth method advertised by any env for the same install. */
+export function findTerminalAuthMethodInStatuses(
+  statuses: readonly AgentStatus[],
+): AgentTerminalAuthMethod | undefined {
+  for (const status of statuses) {
+    const method = findTerminalAuthMethodForStatus(status);
+    if (method) return method;
+  }
+  return undefined;
+}
+
 export function agentAuthTarget(status: AgentStatus): {
   envKind?: AgentStatus["envKind"];
   wslDistro?: string;

src/renderer/views/SettingsOverlay/parts/SingleAgentSettings.test.tsx

@@ -639,6 +639,28 @@ describe("SingleAgentSettings", () => {
     });
   });
 
+  it("shows auth controls when probe advertised methods but authState is still unknown", () => {
+    statusesState.agentStatuses = [
+      makeStatus("acp-generic:factory-droid", {
+        label: "Factory Droid",
+        authState: "unknown",
+        authMethods: [
+          { id: "login", name: "Login" },
+          {
+            id: "factory-key",
+            name: "Factory API Key",
+            vars: [{ name: "FACTORY_API_KEY", label: "Factory API Key" }],
+          } as never,
+        ],
+      }),
+    ];
+
+    render(<SingleAgentSettings agentKind="acp-generic:factory-droid" />);
+
+    expect(screen.getByLabelText("Factory API Key")).toBeInTheDocument();
+    expect(screen.getByRole("button", { name: "Login" })).toBeInTheDocument();
+  });
+
   it("offers logout (not re-login) for an authenticated ACP agent env", async () => {
     statusesState.agentStatuses = [
       makeStatus("acp-generic:sso-agent", {
@@ -716,6 +738,33 @@ describe("SingleAgentSettings", () => {
     await waitFor(() => expect(refreshAgentStatusesMock).toHaveBeenCalled());
   });
 
+  it("shows Windows login when WSL is signed in but Windows status omitted auth methods", () => {
+    statusesState.agentStatuses = [
+      makeStatus("acp-generic:factory-droid", {
+        label: "Factory Droid",
+        authState: "unknown",
+        envKind: "windows",
+      }),
+    ];
+    statusesState.wslAgentStatuses = [
+      makeStatus("acp-generic:factory-droid", {
+        label: "Factory Droid",
+        authState: "authenticated",
+        authMethods: [{ id: "login", name: "Login" }],
+        envKind: "wsl",
+        envDistro: "Ubuntu",
+      }),
+    ];
+
+    render(<SingleAgentSettings agentKind="acp-generic:factory-droid" />);
+
+    expect(screen.getByText(/Windows · Login required/u)).toBeInTheDocument();
+    expect(screen.getByText(/Complete Login sign-in for Windows\./u)).toBeInTheDocument();
+    expect(screen.getByRole("button", { name: /login windows/i })).toBeInTheDocument();
+    expect(screen.getByText(/WSL \(Ubuntu\) · Signed in/u)).toBeInTheDocument();
+    expect(screen.queryByText(/Windows · Authentication/u)).toBeNull();
+  });
+
   it("labels the remaining WSL auth action when Windows is already signed in", async () => {
     statusesState.agentStatuses = [
       makeStatus("acp-generic:factory-droid", {

src/renderer/views/SettingsOverlay/parts/SingleAgentSettings.tsx

@@ -33,8 +33,10 @@ import {
   acpGenericInstanceId,
   agentAuthTarget,
   envLabelForStatus,
+  findAgentAuthMethodInStatuses,
   findProjectForStatus,
   findTerminalAuthMethodForStatus,
+  findTerminalAuthMethodInStatuses,
   isAgentAuthMethod,
   isEnvVarAuthMethod,
   isTerminalAuthMethod,
@@ -444,8 +446,9 @@ function AcpAgentAuthEnvRow(props: {
   onLogout: () => void;
 }) {
   const { status, authMethod, showEnvironmentLabel } = props;
-  const isMissing = status.authState === "missing";
   const isAuthenticated = status.authState === "authenticated";
+  const isMissing =
+    status.authState === "missing" || (status.authState === "unknown" && authMethod !== undefined);
   const env = envLabel(status);
   const envSuffix = showEnvironmentLabel && env ? ` ${env}` : "";
   const envScope = env ? ` for ${env}` : "";
@@ -669,7 +672,18 @@ export function SingleAgentSettings(props: { agentKind: string }) {
     const method = status.authMethods?.find(isAgentAuthMethod);
     return method ? [{ status, method }] : [];
   });
-  const agentAuth = findAgentAuthMethod(agentAuthStatuses);
+  const sharedAgentAuthMethod = findAgentAuthMethodInStatuses(installedStatuses);
+  const sharedTerminalAuthMethod = findTerminalAuthMethodInStatuses(installedStatuses);
+  const agentAuth =
+    findAgentAuthMethod(agentAuthStatuses) ??
+    (sharedAgentAuthMethod
+      ? {
+          status:
+            agentAuthStatuses.find((status) => status.authMethods?.some(isAgentAuthMethod)) ??
+            installedStatuses[0]!,
+          method: sharedAgentAuthMethod,
+        }
+      : undefined);
   const loginStatus =
     findTerminalLoginStatus(installedStatuses) ??
     missingAuthStatuses.find((status) => status.loginCommand);
@@ -817,20 +831,27 @@ export function SingleAgentSettings(props: { agentKind: string }) {
         setAuthPendingEnvKey(undefined);
       });
   };
+  const hasAdvertisedAuthMethods = installedStatuses.some(
+    (status) => (status.authMethods?.length ?? 0) > 0,
+  );
   const hasAuthSettings =
     envVarAuthMethod !== undefined ||
     agentAuth !== undefined ||
     loginCommand !== undefined ||
     missingAuthStatuses.length > 0 ||
-    logoutStatuses.length > 0;
+    logoutStatuses.length > 0 ||
+    hasAdvertisedAuthMethods;
   const includeAuthFallbackMetadata = !hasAuthSettings;
   const metadataStatuses = installedStatuses.filter(
     (status) =>
       formatAgentMetadataSummary(status, {
         includeAuthFallback: includeAuthFallbackMetadata,
       }) !== undefined,
   );
-  const authMissing = missingAuthStatuses.length > 0;
+  const authMissing =
+    missingAuthStatuses.length > 0 ||
+    (hasAdvertisedAuthMethods &&
+      !installedStatuses.some((status) => status.authState === "authenticated"));
   const missingAuthLabel = formatStatusList(missingAuthStatuses);
   const showAuthEnvironmentLabels = installedStatuses.length > 1;
   const showEnvVarOnly = envVarAuthMethod !== undefined && !authMissing;
@@ -1177,9 +1198,17 @@ export function SingleAgentSettings(props: { agentKind: string }) {
               ) : null}
               {installedStatuses.map((status) => {
                 const envKey = statusEnvKey(status);
-                const agentMethod = status.authMethods?.find(isAgentAuthMethod);
-                const terminalMethod = findTerminalAuthMethodForStatus(status);
+                const agentMethod =
+                  status.authMethods?.find(isAgentAuthMethod) ?? sharedAgentAuthMethod;
+                const terminalMethod =
+                  findTerminalAuthMethodForStatus(status) ?? sharedTerminalAuthMethod;
                 const method = agentMethod ?? terminalMethod;
+                const isAuthenticated = status.authState === "authenticated";
+                const needsInteractiveRow =
+                  isAuthenticated ||
+                  status.authState === "missing" ||
+                  (status.authState === "unknown" && method !== undefined);
+                if (!needsInteractiveRow) return null;
                 return (
                   <AcpAgentAuthEnvRow
                     key={`${status.kind}-${envKey}-auth-row`}