feat: integrate meeting bot frontend

[Rishavraaj]

Summary

• Connected all meeting UI components (previously using hardcoded dummy
  data) to the real backend API
• Created a typed meetingsApi client and wired up React Query hooks for
  data fetching and mutations
• Fixed two backend bugs blocking meeting creation

Changes

Frontend

• src/lib/api/meetings.ts — new API client with full TypeScript types
  (Meeting, MeetingActionItem, MeetingSummary, TranscriptData) and
  methods: getMeetings, getMeeting, createMeeting, deleteMeeting,
  endMeeting, updateActionItem
• meeting-list.tsx — replaced hardcoded array with useQuery; delete
  wired to useMutation with cache invalidation; empty state now shows "Add
  to a meeting" CTA
• meeting-detail.tsx — replaced dummy object with useQuery; polls
  every 5s during IN_PROGRESS/PROCESSING; End Meeting button calls POST /meetings/:id/end; loading and not-found states added
• add-meeting.tsx — form submission wired to useMutation; redirects
  to detail page on success; removed unused projectId field
• meetings/page.tsx + meeting/[id]/page.tsx — added
  prefetchQuery for SSR hydration

Backend

• meeting.controller.ts — moved ZodPipe from @UsePipes
  (method-level) to @Body() (parameter-level) on create and
  addTranscriptChunk; method-level pipes validate all params including
  @OrgId() organizationId: number, causing every create request to fail
  with "expected object, received number"
• meeting.dto.ts — scheduledAt now uses z.string().datetime({ offset: true }) to accept ISO 8601 strings with timezone offset (e.g.
  +05:30)
• meeting.service.ts — findOne now constructs a public S3 URL
  (recordingUrl) from the stored key and returns transcriptData (parsed
  transcript array) alongside chatMessages

Test Plan

• /meetings — list loads from DB; empty state shows CTA button
• Add meeting form — submit with a Google Meet URL → POST /meetings
  succeeds, redirects to detail page
• Meeting detail — status badge, recording, transcript, chat, summary,
  action items tabs all render from real API data
• End Meeting button visible on IN_PROGRESS meetings, sends signal to
  bot
• Delete meeting from list — removed and list refreshes