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>

server/reflector/ws_events.py

@@ -0,0 +1,188 @@
+"""Typed WebSocket event models.
+
+Defines Pydantic models with Literal discriminators for all WS events.
+Exposed via stub GET endpoints so ``pnpm openapi`` generates TS discriminated unions.
+"""
+
+from typing import Annotated, Literal, Union
+
+from pydantic import BaseModel, Discriminator
+
+from reflector.db.transcripts import (
+    TranscriptActionItems,
+    TranscriptDuration,
+    TranscriptFinalLongSummary,
+    TranscriptFinalShortSummary,
+    TranscriptFinalTitle,
+    TranscriptStatus,
+    TranscriptText,
+    TranscriptWaveform,
+)
+from reflector.utils.string import NonEmptyString
+from reflector.views.transcripts import GetTranscriptTopic
+
+# ---------------------------------------------------------------------------
+# Transcript-level event name literal
+# ---------------------------------------------------------------------------
+
+TranscriptEventName = Literal[
+    "TRANSCRIPT",
+    "TOPIC",
+    "STATUS",
+    "FINAL_TITLE",
+    "FINAL_LONG_SUMMARY",
+    "FINAL_SHORT_SUMMARY",
+    "ACTION_ITEMS",
+    "DURATION",
+    "WAVEFORM",
+]
+
+# ---------------------------------------------------------------------------
+# Transcript-level WS event wrappers
+# ---------------------------------------------------------------------------
+
+
+class TranscriptWsTranscript(BaseModel):
+    event: Literal["TRANSCRIPT"] = "TRANSCRIPT"
+    data: TranscriptText
+
+
+class TranscriptWsTopic(BaseModel):
+    event: Literal["TOPIC"] = "TOPIC"
+    data: GetTranscriptTopic
+
+
+class TranscriptWsStatusData(BaseModel):
+    value: TranscriptStatus
+
+
+class TranscriptWsStatus(BaseModel):
+    event: Literal["STATUS"] = "STATUS"
+    data: TranscriptWsStatusData
+
+
+class TranscriptWsFinalTitle(BaseModel):
+    event: Literal["FINAL_TITLE"] = "FINAL_TITLE"
+    data: TranscriptFinalTitle
+
+
+class TranscriptWsFinalLongSummary(BaseModel):
+    event: Literal["FINAL_LONG_SUMMARY"] = "FINAL_LONG_SUMMARY"
+    data: TranscriptFinalLongSummary
+
+
+class TranscriptWsFinalShortSummary(BaseModel):
+    event: Literal["FINAL_SHORT_SUMMARY"] = "FINAL_SHORT_SUMMARY"
+    data: TranscriptFinalShortSummary
+
+
+class TranscriptWsActionItems(BaseModel):
+    event: Literal["ACTION_ITEMS"] = "ACTION_ITEMS"
+    data: TranscriptActionItems
+
+
+class TranscriptWsDuration(BaseModel):
+    event: Literal["DURATION"] = "DURATION"
+    data: TranscriptDuration
+
+
+class TranscriptWsWaveform(BaseModel):
+    event: Literal["WAVEFORM"] = "WAVEFORM"
+    data: TranscriptWaveform
+
+
+TranscriptWsEvent = Annotated[
+    Union[
+        TranscriptWsTranscript,
+        TranscriptWsTopic,
+        TranscriptWsStatus,
+        TranscriptWsFinalTitle,
+        TranscriptWsFinalLongSummary,
+        TranscriptWsFinalShortSummary,
+        TranscriptWsActionItems,
+        TranscriptWsDuration,
+        TranscriptWsWaveform,
+    ],
+    Discriminator("event"),
+]
+
+# ---------------------------------------------------------------------------
+# User-level event name literal
+# ---------------------------------------------------------------------------
+
+UserEventName = Literal[
+    "TRANSCRIPT_CREATED",
+    "TRANSCRIPT_DELETED",
+    "TRANSCRIPT_STATUS",
+    "TRANSCRIPT_FINAL_TITLE",
+    "TRANSCRIPT_DURATION",
+]
+
+# ---------------------------------------------------------------------------
+# User-level WS event data models
+# ---------------------------------------------------------------------------
+
+
+class UserTranscriptCreatedData(BaseModel):
+    id: NonEmptyString
+
+
+class UserTranscriptDeletedData(BaseModel):
+    id: NonEmptyString
+
+
+class UserTranscriptStatusData(BaseModel):
+    id: NonEmptyString
+    value: TranscriptStatus
+
+
+class UserTranscriptFinalTitleData(BaseModel):
+    id: NonEmptyString
+    title: NonEmptyString
+
+
+class UserTranscriptDurationData(BaseModel):
+    id: NonEmptyString
+    duration: float
+
+
+# ---------------------------------------------------------------------------
+# User-level WS event wrappers
+# ---------------------------------------------------------------------------
+
+
+class UserWsTranscriptCreated(BaseModel):
+    event: Literal["TRANSCRIPT_CREATED"] = "TRANSCRIPT_CREATED"
+    data: UserTranscriptCreatedData
+
+
+class UserWsTranscriptDeleted(BaseModel):
+    event: Literal["TRANSCRIPT_DELETED"] = "TRANSCRIPT_DELETED"
+    data: UserTranscriptDeletedData
+
+
+class UserWsTranscriptStatus(BaseModel):
+    event: Literal["TRANSCRIPT_STATUS"] = "TRANSCRIPT_STATUS"
+    data: UserTranscriptStatusData
+
+
+class UserWsTranscriptFinalTitle(BaseModel):
+    event: Literal["TRANSCRIPT_FINAL_TITLE"] = "TRANSCRIPT_FINAL_TITLE"
+    data: UserTranscriptFinalTitleData
+
+
+class UserWsTranscriptDuration(BaseModel):
+    event: Literal["TRANSCRIPT_DURATION"] = "TRANSCRIPT_DURATION"
+    data: UserTranscriptDurationData
+
+
+UserWsEvent = Annotated[
+    Union[
+        UserWsTranscriptCreated,
+        UserWsTranscriptDeleted,
+        UserWsTranscriptStatus,
+        UserWsTranscriptFinalTitle,
+        UserWsTranscriptDuration,
+    ],
+    Discriminator("event"),
+]