Summary

Extends the existing Gmail piece with the missing actions and triggers requested in #8072:

New Actions (6)

• Add Label to Email — Attach a label to an individual email message
• Remove Label from Email — Remove a specific label from an email message
• Create Label — Create a new user label in Gmail (with visibility options)
• Archive Email — Archive an email by removing the INBOX label
• Delete Email — Move an email to Trash
• Remove Label from Thread — Strip a label from all emails in a thread

New Trigger (1)

• New Starred Email — Fires when an email is starred, using Gmail History API with labelAdded for STARRED

Registered Existing Components

• New Conversation trigger (file existed but was not registered in index.ts)
• Get Thread action (file existed but was not registered in index.ts)

OAuth Scope Changes

Added gmail.modify and gmail.labels scopes required for label management and message modification operations.

Implementation Details

• All new actions follow the existing piece patterns using googleapis OAuth2Client
• Label actions use gmail.users.messages.modify / gmail.users.threads.modify API
• Archive uses removeLabelIds: ['INBOX'], Delete uses gmail.users.messages.trash
• Starred trigger uses History API (labelAdded with STARRED label ID) for real-time detection
• Test mode for starred trigger fetches starred emails from the last 2 days
• Version bumped from 0.11.4 to 0.12.0

Test Plan

• Verify Add Label to Email adds specified label to a message
• Verify Remove Label from Email removes specified label from a message
• Verify Create Label creates a new user label with correct visibility settings
• Verify Archive Email removes INBOX label (email moves to All Mail)
• Verify Delete Email moves message to Trash
• Verify Remove Label from Thread strips label from all messages in thread
• Verify New Starred Email trigger fires when an email is starred
• Verify New Conversation trigger detects new thread creation
• Verify Get Thread action returns thread data by ID
• Verify existing actions/triggers still work correctly after scope changes

Fixes #8072 /claim #8072