feat(connectors): add Google Meet knowledge base connector (#5149)

* feat(connectors): add Google Meet knowledge base connector

Syncs Google Meet meeting transcripts into a knowledge base via the Meet
REST API v2. Lists conference records, fetches transcript entries lazily
per meeting (contentDeferred), resolves speaker display names, and maps
participants/duration/meeting-date tags. OAuth via the existing google-meet
provider (meetings.space.readonly).

* fix(connectors): finalize Google Meet transcripts before indexing

- Only index a meeting once every transcript is FILE_GENERATED, so a
  partial transcript is never stored under an endTime-keyed hash that
  would never refresh
- Sort merged transcript entries by start time to preserve chronology
  across multiple transcripts in one conference

* refactor(connectors): dedicated TRANSCRIPTS_PAGE_SIZE constant for Meet transcripts

* fix(connectors): only flag Meet listing capped when cap truncates source

Previously listingCapped was set whenever the fetched count reached
maxMeetings, even when the API returned every record and no next page
existed. That suppressed the sync engine's deletion reconciliation when
the cap happened to equal the true source size. Now flag only when more
pages remain or records were dropped from the page.

Author: waleedlatif1