feat: support Codex goal slash command

web/src/chat/reducer.ts

@@ -1,5 +1,6 @@
 import type { AgentState } from '@/types/api'
-import type { ChatBlock, NormalizedMessage, UsageData } from '@/chat/types'
+import type { AgentEvent, ChatBlock, NormalizedMessage, UsageData } from '@/chat/types'
+import type { ThreadGoal } from '@/types/api'
 import { traceMessages, type TracedMessage } from '@/chat/tracer'
 import { dedupeAgentEvents, foldApiErrorEvents } from '@/chat/reducerEvents'
 import { collectTitleChanges, collectToolIdsFromMessages, ensureToolBlock, getPermissions } from '@/chat/reducerTools'
@@ -27,10 +28,23 @@ export type LatestUsage = {
     timestamp: number
 }
 
+function getLatestThreadGoal(normalized: NormalizedMessage[]): ThreadGoal | null {
+    for (let i = normalized.length - 1; i >= 0; i--) {
+        const msg = normalized[i]
+        if (msg.role !== 'event') continue
+        const event = msg.content as AgentEvent
+        if (event.type === 'thread-goal-cleared') return null
+        if (event.type === 'thread-goal-updated') {
+            return (event as { goal?: ThreadGoal }).goal ?? null
+        }
+    }
+    return null
+}
+
 export function reduceChatBlocks(
     normalized: NormalizedMessage[],
     agentState: AgentState | null | undefined
-): { blocks: ChatBlock[]; hasReadyEvent: boolean; latestUsage: LatestUsage | null } {
+): { blocks: ChatBlock[]; hasReadyEvent: boolean; latestUsage: LatestUsage | null; latestGoal: ThreadGoal | null } {
     const permissionsById = getPermissions(agentState)
     const toolIdsInMessages = collectToolIdsFromMessages(normalized)
     const titleChangesByToolUseId = collectTitleChanges(normalized)
@@ -116,5 +130,10 @@ export function reduceChatBlocks(
         }
     }
 
-    return { blocks: dedupeAgentEvents(foldApiErrorEvents(rootResult.blocks)), hasReadyEvent, latestUsage }
+    return {
+        blocks: dedupeAgentEvents(foldApiErrorEvents(rootResult.blocks)),
+        hasReadyEvent,
+        latestUsage,
+        latestGoal: getLatestThreadGoal(normalized)
+    }
 }