Align task and observe labels with explorer rename

The explore→explorer director rename updated fixtures to agentId
explorer but left five assertions expecting the old Explore/explore
display strings. Title-cased agent ids and observe labels correctly
paint Explorer/explorer; update the expectations to match.

Author: TheGreatAxios

src/tui/chrome-state.test.ts

@@ -117,7 +117,7 @@ describe("formatChromeZones", () => {
     expect(out.task).toBeNull();
     expect(out.agents).toEqual([
       {
-        label: "observe: explore — map callers of openListOverlay",
+        label: "observe: explorer — map callers of openListOverlay",
         tail: "",
         stalled: false,
         kind: "lane",
@@ -580,7 +580,7 @@ describe("chromeFromSession", () => {
     });
     expect(formatChromeZones(state, NOW).agents).toEqual([
       {
-        label: "observe: explore — watch",
+        label: "observe: explorer — watch",
         tail: "",
         stalled: false,
         kind: "lane",

src/tui/diff-rows.test.ts

@@ -130,7 +130,7 @@ describe("diff transcript rows", () => {
 
     // Structural: summary set, not raw args; detail expands with real newlines.
     expect(row.summary).toBe("map callers of leaveObserve");
-    expect(row.verb).toBe("Explore");
+    expect(row.verb).toBe("Explorer");
     expect(row.text).toBe(args); // clipboard still has raw; paint must not use it
     expect(row.summary).not.toContain("success_criteria");
     expect(row.summary).not.toContain("maxTurns");

src/tui/tool-formatter.test.ts

@@ -316,7 +316,7 @@ describe("describeToolCall for task tool", () => {
     const prompt = "Find every call site of leaveObserve and report them.";
     const args = JSON.stringify({ agent: "explorer", prompt, intent: "explore" });
     const result = describeToolCall("task", args);
-    expect(result.display).toBe("Explore");
+    expect(result.display).toBe("Explorer");
     // ARG_VALUE_MAX = 48 with ellipsis when truncated
     expect(result.summary.length).toBeLessThanOrEqual(48);
     expect(result.full).toBe(prompt);
@@ -419,7 +419,7 @@ describe("task activity transcript lines", () => {
 
   test("mergedToolCollapsedPreview curates task call+result into one line", () => {
     const line = mergedToolCollapsedPreview("task", JSON.stringify(fullBrief), reportBody, false);
-    expect(line).toBe("Explore map callers of leaveObserve — Found 3 call sites in app.tsx");
+    expect(line).toBe("Explorer map callers of leaveObserve — Found 3 call sites in app.tsx");
     expect(line).not.toContain("prompt");
     expect(line).not.toContain("maxTurns");
     expect(line).not.toContain("## Summary");