refactor(agents): drop ZWSP prefixes from agent display names

The sort shim from the previous commit enforces canonical core ordering at runtime, so ZWSP prefixes are no longer needed. Removing them eliminates the Bun.stringWidth vs terminal-width drift that broke the TUI status bar (#3259).

Drop AGENT_LIST_SORT_PREFIXES and getAgentRuntimeName from agent-display-names; switch all call sites to getAgentDisplayName. getAgentListDisplayName stays as a thin alias for external importers.

Keep stripInvisibleAgentCharacters and the ZWSP regex paths so legacy session state and configs from v3.14.0-v3.16.0 still resolve.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/plugin-handlers/agent-key-remapper.test.ts

@@ -1,6 +1,6 @@
 import { describe, it, expect } from "bun:test"
 import { remapAgentKeysToDisplayNames } from "./agent-key-remapper"
-import { getAgentDisplayName, getAgentListDisplayName, getAgentRuntimeName } from "../shared/agent-display-names"
+import { getAgentDisplayName, getAgentListDisplayName } from "../shared/agent-display-names"
 
 describe("remapAgentKeysToDisplayNames", () => {
   it("remaps known agent keys to display names", () => {
@@ -124,22 +124,22 @@ describe("remapAgentKeysToDisplayNames", () => {
       getAgentListDisplayName("atlas"),
     ])
     expect(result[getAgentListDisplayName("sisyphus")]).toEqual({
-      name: getAgentRuntimeName("sisyphus"),
+      name: getAgentListDisplayName("sisyphus"),
       prompt: "test",
       mode: "primary",
     })
     expect(result[getAgentListDisplayName("hephaestus")]).toEqual({
-      name: getAgentRuntimeName("hephaestus"),
+      name: getAgentListDisplayName("hephaestus"),
       prompt: "test",
       mode: "primary",
     })
     expect(result[getAgentListDisplayName("prometheus")]).toEqual({
-      name: getAgentRuntimeName("prometheus"),
+      name: getAgentListDisplayName("prometheus"),
       prompt: "test",
       mode: "primary",
     })
     expect(result[getAgentListDisplayName("atlas")]).toEqual({
-      name: getAgentRuntimeName("atlas"),
+      name: getAgentListDisplayName("atlas"),
       prompt: "test",
       mode: "primary",
     })
@@ -160,24 +160,41 @@ describe("remapAgentKeysToDisplayNames", () => {
 
     // then runtime-facing names stay aligned even when builtin configs omit name
     expect(result[getAgentListDisplayName("sisyphus")]).toEqual({
-      name: getAgentRuntimeName("sisyphus"),
+      name: getAgentListDisplayName("sisyphus"),
       prompt: "test",
       mode: "primary",
     })
     expect(result[getAgentListDisplayName("hephaestus")]).toEqual({
-      name: getAgentRuntimeName("hephaestus"),
+      name: getAgentListDisplayName("hephaestus"),
       prompt: "test",
       mode: "primary",
     })
     expect(result[getAgentListDisplayName("prometheus")]).toEqual({
-      name: getAgentRuntimeName("prometheus"),
+      name: getAgentListDisplayName("prometheus"),
       prompt: "test",
       mode: "primary",
     })
     expect(result[getAgentListDisplayName("atlas")]).toEqual({
-      name: getAgentRuntimeName("atlas"),
+      name: getAgentListDisplayName("atlas"),
       prompt: "test",
       mode: "primary",
     })
   })
+
+  it("emits a single literal display-name row with no ZWSP for a single core agent", () => {
+    // given a single core agent input
+    const agents = {
+      sisyphus: { foo: "bar" },
+    }
+
+    // when remapping
+    const result = remapAgentKeysToDisplayNames(agents)
+
+    // then exactly one row is emitted under the clean literal display name
+    expect(Object.keys(result)).toEqual(["Sisyphus - Ultraworker"])
+    expect(result["Sisyphus - Ultraworker"]).toEqual({
+      name: "Sisyphus - Ultraworker",
+      foo: "bar",
+    })
+  })
 })