fix: address PR #1300 review follow-up comments

packages/core/src/__tests__/metadata.test.ts

@@ -8,6 +8,7 @@ import {
   readMetadataRaw,
   readCanonicalLifecycle,
   readArchivedMetadataRaw,
+  mutateMetadata,
   writeMetadata,
   updateMetadata,
   deleteMetadata,
@@ -212,6 +213,29 @@ describe("updateMetadata", () => {
     expect(meta!.status).toBe("pr_open");
     expect(meta!.summary).toBeUndefined();
   });
+
+  it("returns the normalized record that is actually persisted", () => {
+    writeMetadata(dataDir, "upd-5", {
+      worktree: "/tmp/w",
+      branch: "main",
+      status: "working",
+      summary: "doing stuff",
+    });
+
+    const next = mutateMetadata(dataDir, "upd-5", (existing) => ({
+      ...existing,
+      summary: "",
+      pr: "https://github.com/org/repo/pull/5",
+    }));
+
+    expect(next).toEqual({
+      worktree: "/tmp/w",
+      branch: "main",
+      status: "working",
+      pr: "https://github.com/org/repo/pull/5",
+    });
+    expect(readMetadataRaw(dataDir, "upd-5")).toEqual(next);
+  });
 });
 
 describe("readCanonicalLifecycle", () => {

packages/core/src/metadata.ts

@@ -193,6 +193,12 @@ function applyMetadataUpdates(
   return next;
 }
 
+function normalizeMetadataRecord(data: Record<string, string>): Record<string, string> {
+  return Object.fromEntries(
+    Object.entries(data).filter(([, value]) => value !== undefined && value !== ""),
+  );
+}
+
 export function mutateMetadata(
   dataDir: string,
   sessionId: SessionId,
@@ -208,7 +214,7 @@ export function mutateMetadata(
     return null;
   }
 
-  const next = updater({ ...existing });
+  const next = normalizeMetadataRecord(updater({ ...existing }));
 
   mkdirSync(dirname(path), { recursive: true });
   atomicWriteFileSync(path, serializeMetadata(next));

packages/web/src/app/globals.css

@@ -1854,6 +1854,11 @@ html.light .xterm .xterm-viewport:hover::-webkit-scrollbar-thumb:active {
   background: var(--color-status-ready);
 }
 
+.session-detail-tone--idle {
+  color: var(--color-status-idle);
+  background: var(--color-status-idle);
+}
+
 .session-detail-tone--attention {
   color: var(--color-status-attention);
   background: var(--color-status-attention);

packages/web/src/components/SessionDetail.tsx

@@ -131,6 +131,8 @@ function activityToneClass(activityColor: string): string {
       return "session-detail-tone--working";
     case "var(--color-status-ready)":
       return "session-detail-tone--ready";
+    case "var(--color-status-idle)":
+      return "session-detail-tone--idle";
     case "var(--color-status-attention)":
       return "session-detail-tone--attention";
     case "var(--color-status-error)":