[Feature Request] Allow project-level control of claude.ai connectors via .mcp.json

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Claude.ai connectors synced from a user's claude.ai account are loaded into every Claude Code session with no way to control them at the project level. The current options are:

1. All connectors everywhere — every project gets every claude.ai connector
2. No connectors anywhere — disable sync globally (e.g., via cachedGrowthBookFeatures.tengu_claudeai_mcp_connectors)
3. Per-session toggle — manually disable via /mcp each session (not persistent)

There is no middle ground. Users cannot specify which claude.ai connectors are relevant for a given project.
Why this matters:

• Tool clutter: Claude may attempt to use connectors that aren't relevant, wasting time and tokens on tool calls that don't help.
• Different projects need different tools: many tools are not relevant for certain projects

Proposed Solution

Allow .mcp.json (or .claude/settings.local.json) to disable specific claude.ai connectors at the project level.

Option A: Disable specific connectors in .mcp.json

{
  "mcpServers": {
    "claude.ai Asana": { "disabled": true },
    "claude.ai Slack": { "disabled": true },
    "claude.ai Notion": { "disabled": true }
  }
}

Option B: A dedicated key for claude.ai connector overrides

{
  "cloudConnectors": {
    "enabled": ["Arc Benchling MCP", "arc-google-sheets-mcp"],
    "disabled": ["Asana", "Slack", "Notion"]
  }
}

Option C: Allowlist mode — only load specified connectors

```json{
"cloudConnectors": {
"mode": "allowlist",
"allow": ["Arc Benchling MCP", "arc-google-sheets-mcp"]
}
}

Any of these would solve the problem. The key requirement is project-level scope — the same user should be able to have different connector configurations for different projects.

### Alternative Solutions

_No response_

### Priority

High - Significant impact on productivity

### Feature Category

MCP server integration

### Use Case Example

A user has 15+ claude.ai connectors configured for use across claude.ai and Claude Code. They work across multiple projects:

* Project A (bioinformatics pipeline): Needs Benchling + Google Sheets connectors. Asana, Slack, and Notion connectors are irrelevant noise.
* Project B (internal web app): Needs Asana + Notion. Benchling connectors are irrelevant.
* Project C (data analysis script): Needs no connectors at all — pure coding task.

Today, all 15 connectors load into every session regardless of project context. The `disallowedTools` setting in `.claude/settings.local.json` can block tool invocation but doesn't prevent the connectors from loading and consuming context.

### Additional Context

_No response_