refactor(agent-display): centralize name normalization resolution

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

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

src/shared/agent-display-names.test.ts

@@ -217,6 +217,10 @@ describe("normalizeAgentForPrompt", () => {
   it("removes zero-width characters before returning canonical names", () => {
     expect(normalizeAgentForPrompt("Sisyphus\u200B - Ultraworker")).toBe("Sisyphus - Ultraworker")
   })
+
+  it("converts legacy parenthesized names to canonical display names", () => {
+    expect(normalizeAgentForPrompt("Atlas (Plan Executor)")).toBe("Atlas - Plan Executor")
+  })
 })
 
 describe("normalizeAgentForPromptKey", () => {
@@ -224,6 +228,10 @@ describe("normalizeAgentForPromptKey", () => {
     expect(normalizeAgentForPromptKey("Sisyphus (Ultraworker)")).toBe("sisyphus")
   })
 
+  it("strips UI ordering prefixes before returning config keys", () => {
+    expect(normalizeAgentForPromptKey(getAgentListDisplayName("atlas"))).toBe("atlas")
+  })
+
   it("preserves custom agents", () => {
     expect(normalizeAgentForPromptKey("MyCustomAgent")).toBe("MyCustomAgent")
   })
@@ -259,7 +267,7 @@ describe("AGENT_DISPLAY_NAMES", () => {
     const httpHeaderUnsafe = /[()]/
 
     // when checking each display name
-    for (const [key, displayName] of Object.entries(AGENT_DISPLAY_NAMES)) {
+    for (const [, displayName] of Object.entries(AGENT_DISPLAY_NAMES)) {
       // then none should contain parentheses
       expect(httpHeaderUnsafe.test(displayName)).toBe(false)
     }