v2.3.1-permission-questions: enrich ACP permission wire for interactive questions and elicitations

The permission_requested WS frame now carries kind ('tool'|'question'|'plan'|
'elicitation'), input (the tool's rawInput payload), and description fields.
PermissionCard detects question-type permissions (Claude Code's AskUserQuestion)
and renders an interactive radio/checkbox form instead of approve/deny buttons.
Submitting answers auto-selects the first allow option.

Also wires up ACP createElicitation (unstable/experimental) — JSON Schema-driven
forms for structured user input. The same PermissionCard renders elicitation
fields with type-appropriate inputs. Both flows use the existing permission-waiter
blocking pattern with 120s timeout.

The response path (POST /api/coder/tasks/:id/permission) now accepts optional
updated_input alongside option_id, forwarded to the ACP agent as the user's
answer payload. Elicitation responses map to accept/decline/cancel actions.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/web/src/api/client.ts

@@ -319,10 +319,10 @@ export const api = {
       }),
     getTaskPermission: (taskId: string) =>
       request<PermissionPrompt>(`/api/coder/tasks/${taskId}/permission`),
-    respondTaskPermission: (taskId: string, optionId: string | null) =>
+    respondTaskPermission: (taskId: string, optionId: string | null, updatedInput?: Record<string, unknown>) =>
       request<{ ok: boolean }>(`/api/coder/tasks/${taskId}/permission`, {
         method: 'POST',
-        body: JSON.stringify({ option_id: optionId }),
+        body: JSON.stringify({ option_id: optionId, ...(updatedInput ? { updated_input: updatedInput } : {}) }),
       }),
     getTaskCommands: (taskId: string) =>
       request<{ taskId: string; commands: AgentCommand[] }>(`/api/coder/tasks/${taskId}/commands`),