fix: live flow real-time updates during processing (#861)

* fix: live flow real-time updates during processing

Three gaps caused transcript pages to require manual refresh after
live recording/processing:

1. UserEventsProvider only invalidated list queries on TRANSCRIPT_STATUS,
   not individual transcript queries. Now parses data.id from the event
   and calls invalidateTranscript for the specific transcript.

2. useWebSockets had no reconnection logic — a dropped WS silently
   killed all real-time updates. Added exponential backoff reconnection
   (1s-30s, max 10 retries) with intentional close detection.

3. No polling fallback — WS was single point of failure. Added
   conditional refetchInterval to useTranscriptGet that polls every 5s
   when transcript status is processing/uploaded/recording.

* feat: type-safe WebSocket events via OpenAPI stub

Define Pydantic models with Literal discriminators for all WS events
(9 transcript-level, 5 user-level). Expose via stub GET endpoints so
pnpm openapi generates TS discriminated unions with exhaustive switch
narrowing on the frontend.

- New server/reflector/ws_events.py with TranscriptWsEvent and UserWsEvent
- Tighten backend emit signatures with TranscriptEventName literal
- Frontend uses generated types, removes Zod schema and manual casts
- Fix pre-existing bugs: waveform mapping, FINAL_LONG_SUMMARY field name
- STATUS value now typed as TranscriptStatus literal end-to-end
- TOPIC handler simplified to query invalidation only (avoids shape mismatch)

* fix: restore TOPIC WS handler with immediate state update

The setTopics call provides instant topic rendering during live
transcription. Query invalidation still follows for full data sync.

* fix: align TOPIC WS event data with GetTranscriptTopic shape

Convert TranscriptTopic → GetTranscriptTopic in pipeline before
emitting, so WS sends segments instead of words. Removes the
`as unknown as Topic` cast on the frontend.

* fix: use NonEmptyString and TranscriptStatus in user WS event models

---------

Co-authored-by: Igor Loskutov <igor.loskutoff@gmail.com>

www/app/lib/UserEventsProvider.tsx

@@ -4,14 +4,12 @@ import React, { useEffect, useRef } from "react";
 import { useQueryClient } from "@tanstack/react-query";
 import { WEBSOCKET_URL } from "./apiClient";
 import { useAuth } from "./AuthProvider";
-import { z } from "zod";
-import { invalidateTranscriptLists, TRANSCRIPT_SEARCH_URL } from "./apiHooks";
+import { invalidateTranscript, invalidateTranscriptLists } from "./apiHooks";
+import { parseNonEmptyString } from "./utils";
+import type { operations } from "../reflector-api";
 
-const UserEvent = z.object({
-  event: z.string(),
-});
-
-type UserEvent = z.TypeOf<typeof UserEvent>;
+type UserWsEvent =
+  operations["v1_user_get_websocket_events"]["responses"][200]["content"]["application/json"];
 
 class UserEventsStore {
   private socket: WebSocket | null = null;
@@ -133,23 +131,26 @@ export function UserEventsProvider({
     if (!detachRef.current) {
       const onMessage = (event: MessageEvent) => {
         try {
-          const msg = UserEvent.parse(JSON.parse(event.data));
-          const eventName = msg.event;
+          const msg: UserWsEvent = JSON.parse(event.data);
 
-          const invalidateList = () => invalidateTranscriptLists(queryClient);
-
-          switch (eventName) {
+          switch (msg.event) {
             case "TRANSCRIPT_CREATED":
             case "TRANSCRIPT_DELETED":
             case "TRANSCRIPT_STATUS":
             case "TRANSCRIPT_FINAL_TITLE":
             case "TRANSCRIPT_DURATION":
-              invalidateList().then(() => {});
-              break;
-
-            default:
-              // Ignore other content events for list updates
+              invalidateTranscriptLists(queryClient).then(() => {});
+              invalidateTranscript(
+                queryClient,
+                parseNonEmptyString(msg.data.id),
+              ).then(() => {});
               break;
+            default: {
+              const _exhaustive: never = msg;
+              console.warn(
+                `Unknown user event: ${(_exhaustive as UserWsEvent).event}`,
+              );
+            }
           }
         } catch (err) {
           console.warn("Invalid user event message", event.data);