refactor(athena): remove dead council types and stale barrel exports

Remove CouncilLaunchFailure, CouncilLaunchedMember, CouncilLaunchResult types and barrel exports for deleted council-orchestrator and council-prompt modules.

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

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

src/agents/athena/index.ts

@@ -2,6 +2,4 @@ export * from "./types"
 export * from "./agent"
 export * from "./council-member-agent"
 export * from "./model-parser"
-export * from "./council-prompt"
-export * from "./council-orchestrator"
 

src/agents/athena/types.ts

@@ -7,21 +7,3 @@ export interface CouncilMemberConfig {
 export interface CouncilConfig {
   members: CouncilMemberConfig[]
 }
-
-export interface CouncilLaunchFailure {
-  member: CouncilMemberConfig
-  error: string
-}
-
-export interface CouncilLaunchedMember {
-  member: CouncilMemberConfig
-  taskId: string
-}
-
-/** Return type of executeCouncil — only tracks launch outcomes, not task completion */
-export interface CouncilLaunchResult {
-  question: string
-  launched: CouncilLaunchedMember[]
-  failures: CouncilLaunchFailure[]
-  totalMembers: number
-}