Add Ranla plugin for Grok Build

[Ktryberceo]

What this PR does

Adds the official Ranla plugin to the Grok plugin marketplace.

• Plugin name: ranla
• Type: remote source
• Source URL + pinned SHA: https://github.com/Super-Send/ranla-grok-plugin.git@274a5f3cad4e09cf41d8a69884f3ad31e500efe3
• Homepage: https://ranla.ai

What Ranla provides

Ranla is an AI growth agent for the signups a product already has. This plugin connects Grok Build to a Ranla workspace through the hosted MCP server. The same workspace also sends transactional email, so application mail does not need a second product.

Surface	What it does
Hosted MCP	https://mcp.ranla.ai/mcp — OAuth in the browser, no API key to paste
arc_message / threads / approvals	Talk to Ranla for growth strategy and gated campaign mutations
arc_* read tools	Audience, campaigns, events, templates, setup status, product context
Skills	ranla (instrument lifecycle in app code) and ranla-mcp (Arc-first MCP usage)
Transactional email (same workspace)	send_email, domains, templates, webhooks, deliverability

Growth campaign mutations stay on Ranla (arc_message + approvals). Transactional send is available on the same MCP when the user needs receipts, auth, or alerts.

Ownership

• I own this plugin or have the right to distribute it.
• The source repo is published under our official org.

Plugin source: Super-Send/ranla-grok-plugin under the official Super-Send organization.

Checklist

• Added exactly one entry in .grok-plugin/marketplace.json with a kebab-case name.
• Remote source pins a full 40-character lowercase commit SHA that is public and reachable.
• Regenerated .grok-plugin/plugin-index.json.
• python3 scripts/validate-catalog.py passes locally.
• python3 scripts/generate-plugin-index.py --check passes locally.
• Homepage and clear description are set.
• License is stated as MIT.

Security

• No curl | bash, remote-code download/exec, or postinstall RCE.
• No reading/exfiltration of secrets, tokens, .env, or env vars.
• Hooks and MCP scope are least-privilege.
• Network endpoints this plugin calls (and why):
  • https://mcp.ranla.ai/mcp — hosted MCP tools
  • https://app.ranla.ai — OAuth authorization / dashboard
  • https://api.ranla.ai — mail and Audience API calls made by the MCP server
• Credentials/permissions it requires (and why):
  • Browser OAuth to a Ranla account on first connect. No embedded secrets. Bearer rnl_… / stx_… is optional for advanced/CI setups only.

The plugin contains no lifecycle hooks or installation scripts. MCP is HTTP-only (no local shell server).

Notes for reviewers

Keywords and domains are brand-scoped (ranla, ranla campaigns, ranla.ai and our app/docs/MCP hosts). Index generation fetched the pinned commit successfully.