refactor(agent): consolidate agent system into unified AgentManager with provider-based architecture

Replace separate ACP and agent-types modules with unified AgentManager using provider pattern. Migrate Claude and Codex implementations to provider-specific clients. Streamline session-agent integration, remove old ACP notification types, and introduce agent timeline events. Delete obsolete documentation and test files. Add AgentRegistry for persistence and agent-stream-based communication pattern.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

packages/app/src/components/agent-list.tsx

@@ -2,51 +2,13 @@ import { View, Text, Pressable, ScrollView } from "react-native";
 import { router } from "expo-router";
 import { StyleSheet, useUnistyles } from "react-native-unistyles";
 import type { Agent } from "@/contexts/session-context";
-import type { AgentStatus } from "@server/server/acp/types";
 import { formatTimeAgo } from "@/utils/time";
+import { getAgentStatusColor, getAgentStatusLabel } from "@/utils/agent-status";
 
 interface AgentListProps {
   agents: Map<string, Agent>;
 }
 
-function getStatusColor(status: AgentStatus): string {
-  switch (status) {
-    case "initializing":
-      return "#FFA500";
-    case "ready":
-      return "#2563EB";
-    case "processing":
-      return "#FACC15";
-    case "completed":
-      return "#10B981";
-    case "failed":
-      return "#EF4444";
-    case "killed":
-      return "#6B7280";
-    default:
-      return "#6B7280";
-  }
-}
-
-function getStatusLabel(status: AgentStatus): string {
-  switch (status) {
-    case "initializing":
-      return "Initializing";
-    case "ready":
-      return "Ready";
-    case "processing":
-      return "Processing";
-    case "completed":
-      return "Completed";
-    case "failed":
-      return "Failed";
-    case "killed":
-      return "Killed";
-    default:
-      return "Unknown";
-  }
-}
-
 export function AgentList({ agents }: AgentListProps) {
   const { theme } = useUnistyles();
   
@@ -62,8 +24,8 @@ export function AgentList({ agents }: AgentListProps) {
   return (
     <ScrollView style={styles.container} showsVerticalScrollIndicator={false}>
       {agentArray.map((agent) => {
-        const statusColor = getStatusColor(agent.status);
-        const statusLabel = getStatusLabel(agent.status);
+        const statusColor = getAgentStatusColor(agent.status);
+        const statusLabel = getAgentStatusLabel(agent.status);
         const timeAgo = formatTimeAgo(agent.lastActivityAt);
 
         return (