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/apiHooks.ts

@@ -7,6 +7,7 @@ import type { components } from "../reflector-api";
 import { useAuth } from "./AuthProvider";
 import { MeetingId } from "./types";
 import { NonEmptyString } from "./utils";
+import type { TranscriptStatus } from "./transcript";
 
 /*
  * XXX error types returned from the hooks are not always correct; declared types are ValidationError but real type could be string or any other
@@ -104,6 +105,12 @@ export function useTranscriptProcess() {
   });
 }
 
+const ACTIVE_TRANSCRIPT_STATUSES = new Set<TranscriptStatus>([
+  "processing",
+  "uploaded",
+  "recording",
+]);
+
 export function useTranscriptGet(transcriptId: NonEmptyString | null) {
   return $api.useQuery(
     "get",
@@ -117,6 +124,10 @@ export function useTranscriptGet(transcriptId: NonEmptyString | null) {
     },
     {
       enabled: !!transcriptId,
+      refetchInterval: (query) => {
+        const status = query.state.data?.status;
+        return status && ACTIVE_TRANSCRIPT_STATUSES.has(status) ? 5000 : false;
+      },
     },
   );
 }