feat: add transcript format parameter to GET endpoint (#709)

* feat: add transcript format parameter to GET endpoint

Add transcript_format query parameter to /v1/transcripts/{id} endpoint
with support for multiple output formats using discriminated unions.

Formats supported:
- text: Plain speaker dialogue (default)
- text-timestamped: Dialogue with [MM:SS] timestamps
- webvtt-named: WebVTT subtitles with participant names
- json: Structured segments with full metadata

Response models use Pydantic discriminated unions with transcript_format
as discriminator field. POST/PATCH endpoints return GetTranscriptWithParticipants
for minimal responses. GET endpoint returns format-specific models.

* Copy transcript format

* Regenerate types

* Fix transcript formats

* Don't throw inside try

* Remove any type

* Toast share copy errors

* transcript_format exhaustiveness and python idiomatic assert_never

* format_timestamp_mmss clear type definition

* Rename seconds_to_timestamp

* Test transcript format with overlapping speakers

* exact match for vtt multispeaker test

---------

Co-authored-by: Sergey Mankovsky <sergey@monadical.com>
Co-authored-by: Igor Loskutov <igor.loskutoff@gmail.com>

www/app/lib/authBackend.ts

@@ -32,6 +32,11 @@ async function getUserId(accessToken: string): Promise<string | null> {
     });
 
     if (!response.ok) {
+      try {
+        console.error(await response.text());
+      } catch (e) {
+        console.error("Failed to parse error response", e);
+      }
       return null;
     }