v2.2-paseo-providers: Paseo provider stack + v2.2.1 pane-scoped chat fixes

Ship Paseo-equivalent provider snapshot, AgentComposerBar, ACP dispatch
rewrite with streaming/persist, permission prompts, and agent commands.
Follow-up: pane-scoped chat resolution, CoderMessageList tool timeline,
WS user-delta replace, and inference orphan tool_call stripping.
Archive openspec v2-2; update CHANGELOG and CURRENT.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/coder/src/services/agent-commands-cache.ts

@@ -0,0 +1,28 @@
+/** In-memory cache of ACP available_commands_update per task. */
+
+import type { AgentCommand } from './provider-types.js';
+import { mergeCommands } from './provider-commands.js';
+
+export type { AgentCommand };
+
+const commandsByTask = new Map<string, AgentCommand[]>();
+
+export function setTaskCommands(taskId: string, commands: AgentCommand[]): void {
+  if (commands.length === 0) return;
+  commandsByTask.set(taskId, commands);
+}
+
+/** Merge by command name; later lists override earlier entries. */
+export function mergeTaskCommands(taskId: string, commands: AgentCommand[]): void {
+  if (commands.length === 0) return;
+  const merged = mergeCommands(commandsByTask.get(taskId) ?? [], commands);
+  commandsByTask.set(taskId, merged);
+}
+
+export function getTaskCommands(taskId: string): AgentCommand[] | null {
+  return commandsByTask.get(taskId) ?? null;
+}
+
+export function clearTaskCommands(taskId: string): void {
+  commandsByTask.delete(taskId);
+}