Control UI: disambiguate duplicate agent session labels (#48209)

* Control UI: disambiguate duplicate agent sessions

* Control UI: avoid prefixed session label collisions

* Control UI: align session defaults typing

---------

Co-authored-by: Val Alexander <68980965+BunsDev@users.noreply.github.com>

ui/src/ui/app-render.helpers.ts

@@ -859,6 +859,70 @@ export function resolveSessionOptionGroups(
     }
   }
 
+  const allOptions = Array.from(groups.values()).flatMap((group) =>
+    group.options.map((option) => ({ groupLabel: group.label, option })),
+  );
+  const labels = new Map(allOptions.map(({ option }) => [option, option.label]));
+  const countAssignedLabels = () => {
+    const counts = new Map<string, number>();
+    for (const { option } of allOptions) {
+      const label = labels.get(option) ?? option.label;
+      counts.set(label, (counts.get(label) ?? 0) + 1);
+    }
+    return counts;
+  };
+  const labelIncludesScopeLabel = (label: string, scopeLabel: string) => {
+    const trimmedScope = scopeLabel.trim();
+    if (!trimmedScope) {
+      return false;
+    }
+    return (
+      label === trimmedScope ||
+      label.endsWith(` · ${trimmedScope}`) ||
+      label.endsWith(` / ${trimmedScope}`)
+    );
+  };
+
+  const globalCounts = countAssignedLabels();
+  for (const { groupLabel, option } of allOptions) {
+    const currentLabel = labels.get(option) ?? option.label;
+    if ((globalCounts.get(currentLabel) ?? 0) <= 1) {
+      continue;
+    }
+    const scopedPrefix = `${groupLabel} / `;
+    if (currentLabel.startsWith(scopedPrefix)) {
+      continue;
+    }
+    // Keep the agent visible once the native select collapses to a single chosen label.
+    labels.set(option, `${groupLabel} / ${currentLabel}`);
+  }
+
+  const scopedCounts = countAssignedLabels();
+  for (const { option } of allOptions) {
+    const currentLabel = labels.get(option) ?? option.label;
+    if ((scopedCounts.get(currentLabel) ?? 0) <= 1) {
+      continue;
+    }
+    if (labelIncludesScopeLabel(currentLabel, option.scopeLabel)) {
+      continue;
+    }
+    labels.set(option, `${currentLabel} · ${option.scopeLabel}`);
+  }
+
+  const finalCounts = countAssignedLabels();
+  for (const { option } of allOptions) {
+    const currentLabel = labels.get(option) ?? option.label;
+    if ((finalCounts.get(currentLabel) ?? 0) <= 1) {
+      continue;
+    }
+    // Fall back to the full key only when every friendlier disambiguator still collides.
+    labels.set(option, `${currentLabel} · ${option.key}`);
+  }
+
+  for (const { option } of allOptions) {
+    option.label = labels.get(option) ?? option.label;
+  }
+
   return Array.from(groups.values());
 }
 

ui/src/ui/views/chat.test.ts

@@ -1035,4 +1035,98 @@ describe("chat view", () => {
     );
     expect(labels).not.toContain("Subagent: cron-config-check");
   });
+
+  it("prefixes duplicate agent session labels with the agent name", () => {
+    const { state } = createChatHeaderState({ omitSessionFromList: true });
+    state.sessionKey = "agent:alpha:main";
+    state.settings.sessionKey = state.sessionKey;
+    state.agentsList = {
+      defaultId: "alpha",
+      mainKey: "agent:alpha:main",
+      scope: "all",
+      agents: [
+        { id: "alpha", name: "Deep Chat" },
+        { id: "beta", name: "Coding" },
+      ],
+    };
+    state.sessionsResult = {
+      ts: 0,
+      path: "",
+      count: 2,
+      defaults: { modelProvider: "openai", model: "gpt-5", contextTokens: null },
+      sessions: [
+        {
+          key: "agent:alpha:main",
+          kind: "direct",
+          updatedAt: null,
+        },
+        {
+          key: "agent:beta:main",
+          kind: "direct",
+          updatedAt: null,
+        },
+      ],
+    };
+    const container = document.createElement("div");
+    render(renderChatSessionSelect(state), container);
+
+    const [sessionSelect] = Array.from(container.querySelectorAll<HTMLSelectElement>("select"));
+    const labels = Array.from(sessionSelect?.querySelectorAll("option") ?? []).map((option) =>
+      option.textContent?.trim(),
+    );
+
+    expect(labels).toContain("Deep Chat (alpha) / main");
+    expect(labels).toContain("Coding (beta) / main");
+    expect(labels).not.toContain("main");
+  });
+
+  it("keeps agent-prefixed labels unique when a custom label already matches the prefix", () => {
+    const { state } = createChatHeaderState({ omitSessionFromList: true });
+    state.sessionKey = "agent:alpha:main";
+    state.settings.sessionKey = state.sessionKey;
+    state.agentsList = {
+      defaultId: "alpha",
+      mainKey: "agent:alpha:main",
+      scope: "all",
+      agents: [
+        { id: "alpha", name: "Deep Chat" },
+        { id: "beta", name: "Coding" },
+      ],
+    };
+    state.sessionsResult = {
+      ts: 0,
+      path: "",
+      count: 3,
+      defaults: { modelProvider: "openai", model: "gpt-5", contextTokens: null },
+      sessions: [
+        {
+          key: "agent:alpha:main",
+          kind: "direct",
+          updatedAt: null,
+        },
+        {
+          key: "agent:beta:main",
+          kind: "direct",
+          updatedAt: null,
+        },
+        {
+          key: "agent:alpha:named-main",
+          kind: "direct",
+          updatedAt: null,
+          label: "Deep Chat (alpha) / main",
+        },
+      ],
+    };
+    const container = document.createElement("div");
+    render(renderChatSessionSelect(state), container);
+
+    const [sessionSelect] = Array.from(container.querySelectorAll<HTMLSelectElement>("select"));
+    const labels = Array.from(sessionSelect?.querySelectorAll("option") ?? []).map((option) =>
+      option.textContent?.trim(),
+    );
+
+    expect(labels.filter((label) => label === "Deep Chat (alpha) / main")).toHaveLength(1);
+    expect(labels).toContain("Deep Chat (alpha) / main · named-main");
+    expect(labels).toContain("Coding (beta) / main");
+  });
 });