Add Google Tasks sync to Tasks module

[Angrigo]

Scope & Context

Users have requested the ability to sync their Google Tasks with TwentyCRM so tasks created/updated in Google are reflected in CRM and vice versa.
This ticket is about adding a first version of the Google Tasks integration in the Tasks module only.

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Current behavior

Currently, the Tasks module in TwentyCRM is completely internal.
There is no sync with external task managers like Google Tasks.

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Expected behavior

• Users should be able to connect their Google account (via OAuth2) and authorize access to Google Tasks.
• Once connected, TwentyCRM should:
  • Display an option "Sync with Google Tasks" in the Tasks module.
  • Create a two-way sync:
    • Tasks created/edited in TwentyCRM appear in Google Tasks.
    • Tasks created/edited in Google Tasks (in the default list) appear in TwentyCRM.
  • Maintain completion status (done/undone).
• Sync should run automatically every X minutes or on-demand via a "Sync now" button.

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Technical inputs

• Use Google Tasks API v1
  Docs: https://developers.google.com/tasks
• Add Google OAuth2 client with https://www.googleapis.com/auth/tasks scope.
• Store tokens in user’s integration settings.
• Create a new sync service:
  • Fetch tasks from Google → upsert in CRM DB.
  • Push new/updated tasks from CRM → Google.
  • Map fields:
    • Title ↔ title
    • Due date ↔ due
    • Notes ↔ notes
    • Status ↔ status (needsAction/completed)
• Add UI changes:
  • Settings → Integrations → Google Tasks (enable/disable).
  • Tasks module → "Sync with Google Tasks" toggle + "Sync now" action.
• Edge cases:
  • Handle deleted tasks (soft-delete in CRM).
  • Handle OAuth token refresh.
  • Avoid infinite loops (use updated_at timestamps and source markers).

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[FelixMalfait]

Thanks for the suggestion! Converted it to a discussion. If we wanted to tackle this I think the only nuance is that we would want the task sync engine to be generic with multiple drivers and not just Google Task (e.g. Linear, Asana, Github issues, etc)