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/server/src/terminal/terminal-manager.ts

@@ -33,12 +33,7 @@ export interface TerminalManager {
   subscribeTerminalsChanged(listener: TerminalsChangedListener): () => void;
 }
 
-type AgentBoundTerminalTitleHandler = (input: { agentId: string; title: string }) => Promise<void> | void;
-
-export function createTerminalManager(options?: {
-  resolveAgentIdForTerminal?: (terminalId: string) => string | null;
-  onAgentBoundTerminalTitleChange?: AgentBoundTerminalTitleHandler;
-}): TerminalManager {
+export function createTerminalManager(): TerminalManager {
   const terminalsByCwd = new Map<string, TerminalSession[]>();
   const terminalsById = new Map<string, TerminalSession>();
   const terminalExitUnsubscribeById = new Map<string, () => void>();
@@ -111,24 +106,8 @@ export function createTerminalManager(options?: {
     const unsubscribeExit = session.onExit(() => {
       removeSessionById(session.id, { kill: false });
     });
-    const unsubscribeTitle = session.onTitleChange((title) => {
+    const unsubscribeTitle = session.onTitleChange(() => {
       emitTerminalsChanged({ cwd: session.cwd });
-      const normalizedTitle = title?.trim();
-      if (!normalizedTitle) {
-        return;
-      }
-      const agentId = options?.resolveAgentIdForTerminal?.(session.id) ?? null;
-      if (!agentId) {
-        return;
-      }
-      void Promise.resolve(
-        options?.onAgentBoundTerminalTitleChange?.({
-          agentId,
-          title: normalizedTitle,
-        }),
-      ).catch(() => {
-        // no-op
-      });
     });
     terminalExitUnsubscribeById.set(session.id, unsubscribeExit);
     terminalTitleUnsubscribeById.set(session.id, unsubscribeTitle);