feat(ui): add summary/action-item types + errorMessage() helper (T7.1, FR-LLM-2/3/4)

Types for SummaryFile/ActionItem/LlmStatus and a confirmActionItems
wrapper + onLlmDone listener, so the frontend can consume what
generate_summary/confirm_action_items already produce on the backend.

Also adds errorMessage(): every backend command rejects with
{ kind, message } (see src-tauri/src/error.rs), not a native Error, so
`e instanceof Error` is always false for it and `String(e)` renders as
the literal text "[object Object]" — found by actually clicking
"Generate summary" against an unreachable Ollama endpoint.

src/lib/api.ts

@@ -8,6 +8,22 @@ import { listen, type UnlistenFn } from "@tauri-apps/api/event";
 export type MeetingId = string;
 export type BackendId = "npu" | "nvidia" | "amd" | "intel" | "cpu";
 
+// Every backend command rejects an `Err` as this shape, not a native Error
+// (see src-tauri/src/error.rs) — `e instanceof Error` is always false for it.
+export interface WaError {
+  kind: string;
+  message: string;
+}
+
+export function errorMessage(e: unknown): string {
+  if (typeof e === "string") return e;
+  if (e instanceof Error) return e.message;
+  if (e && typeof e === "object" && typeof (e as WaError).message === "string") {
+    return (e as WaError).message;
+  }
+  return String(e);
+}
+
 export interface BackendInfo {
   id: BackendId;
   name: string;
@@ -23,6 +39,13 @@ export interface HardwareStatus {
   estRtf: number;
 }
 
+export interface LlmStatus {
+  provider: string; // ollama|custom|off (Phase 10a adds anthropic|openai)
+  reachable: boolean;
+  isLocal: boolean;
+  models: string[];
+}
+
 export interface ModelInfo {
   id: string;
   label: string;
@@ -57,6 +80,28 @@ export interface SpeakerInfo {
   participant_id: string | null;
 }
 
+// Drafted action item from a summary (Phase 5, FR-LLM-3). `id` is only set
+// once `confirmActionItems` has persisted it as a row.
+export interface ActionItem {
+  id: string | null;
+  text: string;
+  owner: string | null;
+  due_at: number | null;
+  confirmed: boolean;
+}
+
+// On-disk shape of summary.json (FR-LLM-2/4) — `null` until generate_summary
+// has run at least once for a meeting.
+export interface SummaryFile {
+  schema: number;
+  generated_at: number;
+  provider: string;
+  model: string;
+  summary_md: string;
+  decisions: string[];
+  action_items: ActionItem[];
+}
+
 // Full meeting detail (get_meeting) — DB row + transcript + speakers + notes.
 export interface Meeting {
   id: MeetingId;
@@ -72,6 +117,7 @@ export interface Meeting {
   segments: TranscriptSegment[];
   speakers: SpeakerInfo[];
   notes_markdown: string;
+  summary: SummaryFile | null;
   calendar_event_id: string | null;
 }
 
@@ -227,7 +273,7 @@ export const api = {
   exportMeeting: (meetingId: MeetingId, dest: string, format: "md" | "bundle") =>
     invoke<string>("export_meeting", { meetingId, dest, format }),
 
-  llmStatus: () => invoke("llm_status"),
+  llmStatus: () => invoke<LlmStatus>("llm_status"),
   // provider ∈ ollama|custom|anthropic|openai|off; apiKey (hosted) → OS credential store (ADR-0011).
   setLlmProvider: (config: {
     provider: string;
@@ -237,6 +283,8 @@ export const api = {
   }) => invoke<void>("set_llm_provider", { config }),
   generateSummary: (meetingId: MeetingId, templateId?: string) =>
     invoke<void>("generate_summary", { meetingId, templateId }),
+  confirmActionItems: (meetingId: MeetingId, items: ActionItem[]) =>
+    invoke<void>("confirm_action_items", { meetingId, items }),
 
   importPst: (path: string, password?: string) => invoke<number>("import_pst", { path, password }),
   listCalendarEvents: (from?: number, to?: number) =>
@@ -316,6 +364,8 @@ export const events = {
   ): Promise<UnlistenFn> => listen("transcript://finalized", (e) => cb(e.payload as never)),
   onLlmToken: (cb: (p: { meetingId: string; text: string }) => void): Promise<UnlistenFn> =>
     listen("llm://token", (e) => cb(e.payload as never)),
+  onLlmDone: (cb: (p: { meetingId: string; summary: SummaryFile }) => void): Promise<UnlistenFn> =>
+    listen("llm://done", (e) => cb(e.payload as never)),
   onModelProgress: (
     cb: (p: { id: string; receivedBytes: number; totalBytes: number | null }) => void,
   ): Promise<UnlistenFn> => listen("model://progress", (e) => cb(e.payload as never)),