refactor: remove terminal agent concept entirely

Remove the "agent can be a terminal" branching from the entire codebase.
An agent is now always a session-backed chat agent. Standalone terminal
infrastructure (terminal component, ANSI handling, terminal-stream-protocol)
is preserved.

Server: delete ManagedTerminalAgent, AgentKind, TerminalExitDetails,
launchTerminalAgent, registerTerminalAgent, handleTerminalAgentExited,
supportsTerminalMode capability, buildTerminalCreate/ResumeCommand from
all providers, terminal agent persistence/projections.

App: delete terminal-agent-panel.tsx, terminal-agent-reopen-store.ts,
terminal/terminalExit fields on agent state, "Terminal Agents" launcher
section, terminal-agent workspace setup flow, terminal badge in agent list.

CLI: remove terminal column from ls, terminal-agent error from send.

60 files changed, -3592 lines

packages/app/src/utils/workspace-navigation.ts

@@ -1,7 +1,6 @@
 import { router } from "expo-router";
 import { useWorkspaceLayoutStore } from "@/stores/workspace-layout-store";
 import { generateDraftId } from "@/stores/draft-keys";
-import { useTerminalAgentReopenStore } from "@/stores/terminal-agent-reopen-store";
 import {
   buildWorkspaceTabPersistenceKey,
   type WorkspaceTabTarget,
@@ -13,7 +12,6 @@ interface PrepareWorkspaceTabInput {
   workspaceId: string;
   target: WorkspaceTabTarget;
   pin?: boolean;
-  requestReopen?: boolean;
 }
 
 interface NavigateToPreparedWorkspaceTabInput extends PrepareWorkspaceTabInput {
@@ -45,13 +43,6 @@ export function prepareWorkspaceTab(input: PrepareWorkspaceTabInput): string {
     useWorkspaceLayoutStore.getState().pinAgent(key, target.agentId);
   }
 
-  if (input.requestReopen && target.kind === "agent") {
-    useTerminalAgentReopenStore.getState().requestReopen({
-      serverId: input.serverId,
-      agentId: target.agentId,
-    });
-  }
-
   return buildHostWorkspaceRoute(input.serverId, input.workspaceId);
 }