docs(agent-mode): note AgentDiffView + edit-diff sourcing; formatting

Phase 6: document the read-only AgentDiffView and where edit diffs are sourced
in agentMode/AGENTS.md, and apply prettier formatting. Full jest suite (4384
tests), eslint (incl. boundaries), and the production build are all green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/agentMode/AGENTS.md

@@ -94,6 +94,12 @@ Then in either case:
 - "Knows about a specific binary, install path, BYOK keys, vendor models" → `backends/<id>/`
 - "React component or modal" → `ui/` (generic) or `backends/<id>/`
   (backend-specific)
+- "Read-only `AgentDiffView` (editor pane, view type
+  `copilot-agent-diff-view`, opened via `openAgentDiffView`) rendering an
+  agent edit diff — sourced from the Claude SDK's `tool_use_result`
+  (`structuredPatch`/`originalFile`, parsed in `sdk/sdkEditResult.ts`) for
+  completed edits, from ACP `{type:"diff"}` content otherwise, and
+  synthesized from tool input for permission-card previews" → `ui/`
 - "Canonical-store skill discovery, symlink lifecycle, SKILL.md
   parser/serializer, Skills settings tab (reads `backends/registry.ts`
   for the brand list)" → `skills/`

src/agentMode/sdk/sdkEditResult.test.ts

@@ -52,7 +52,13 @@ describe("readSdkFileEditResult", () => {
       newString: "$& $$ $` $1",
       originalFile: "before TOKEN after",
       structuredPatch: [
-        { oldStart: 1, oldLines: 1, newStart: 1, newLines: 1, lines: ["-before TOKEN after", "+before $& $$ $` $1 after"] },
+        {
+          oldStart: 1,
+          oldLines: 1,
+          newStart: 1,
+          newLines: 1,
+          lines: ["-before TOKEN after", "+before $& $$ $` $1 after"],
+        },
       ],
       userModified: false,
       replaceAll: false,
@@ -71,7 +77,13 @@ describe("readSdkFileEditResult", () => {
       newString: "X",
       originalFile: "dup then dup",
       structuredPatch: [
-        { oldStart: 1, oldLines: 1, newStart: 1, newLines: 1, lines: ["-dup then dup", "+X then dup"] },
+        {
+          oldStart: 1,
+          oldLines: 1,
+          newStart: 1,
+          newLines: 1,
+          lines: ["-dup then dup", "+X then dup"],
+        },
       ],
       userModified: false,
       replaceAll: false,
@@ -106,7 +118,13 @@ describe("readSdkFileEditResult", () => {
       filePath: "/vault/note.md",
       content: "the full new file body",
       structuredPatch: [
-        { oldStart: 1, oldLines: 1, newStart: 1, newLines: 1, lines: ["-old", "+the full new file body"] },
+        {
+          oldStart: 1,
+          oldLines: 1,
+          newStart: 1,
+          newLines: 1,
+          lines: ["-old", "+the full new file body"],
+        },
       ],
       originalFile: "old",
     };

src/agentMode/ui/ActionCard.tsx

@@ -35,8 +35,7 @@ export const ActionCard: React.FC<ActionCardProps> = ({ part, inline }) => {
   // A completed edit whose before/after we can resolve gets the pane treatment:
   // an inline +/− chip and a whole-row click that opens the diff view. Non-edit
   // tools yield null here, so they keep the classic expand/file-open behavior.
-  const editDiff =
-    part.status === "completed" ? deriveEditDiff(part, summaryCtx) : null;
+  const editDiff = part.status === "completed" ? deriveEditDiff(part, summaryCtx) : null;
   const isEditWithDiff = editDiff !== null;
   const stats = editDiff ? diffStats(editDiff) : null;
 
@@ -57,9 +56,7 @@ export const ActionCard: React.FC<ActionCardProps> = ({ part, inline }) => {
       ? (summary.targetPath?.(part, summaryCtx) ?? null)
       : null;
 
-  const openDiff = editDiff
-    ? () => openAgentDiffView(app, editDiff)
-    : undefined;
+  const openDiff = editDiff ? () => openAgentDiffView(app, editDiff) : undefined;
   const rowInteractive = isEditWithDiff || expandable;
 
   const headerClasses = cn(

src/agentMode/ui/editDiff.ts

@@ -26,10 +26,7 @@ interface EditInput {
  * with `toolSummaries` so the alias list can't drift between the two.
  */
 export function rawEditPath(input: unknown): string | null {
-  const i = input as
-    | { file_path?: unknown; filePath?: unknown; path?: unknown }
-    | null
-    | undefined;
+  const i = input as { file_path?: unknown; filePath?: unknown; path?: unknown } | null | undefined;
   if (typeof i?.file_path === "string") return i.file_path;
   if (typeof i?.filePath === "string") return i.filePath;
   if (typeof i?.path === "string") return i.path;