fix(professional-crm): remove Accept header patch causing SSE reconnect loop

[Promithius-DR]

Problem

The POST /mcp handler patches every incoming request to add Accept: application/json, text/event-stream before passing it to StreamableHTTPTransport. When StreamableHTTPTransport sees text/event-stream in the Accept header, it switches to SSE response mode.

Supabase edge functions are stateless — they terminate after each response. An SSE stream that terminates immediately looks like a dropped connection to the MCP client, which reconnects every ~2 seconds. This results in ~43,000 Supabase invocations per day with zero actual tool usage.

Root Cause

// This block forces SSE mode on every request ❌
if (!c.req.header("accept")?.includes("text/event-stream")) {
  const headers = new Headers(c.req.raw.headers);
  headers.set("Accept", "application/json, text/event-stream");
  // ...patches request
}

Fix

Remove the Accept header patch entirely. StreamableHTTPTransport is designed for request/response — without the SSE accept header, it responds with plain JSON, the edge function terminates cleanly, and the client only calls again when it needs to invoke a tool.

Claude Code (the primary consumer of this extension) sends correct Streamable HTTP headers and does not need this workaround.

Impact

• Eliminates ~43k idle Supabase invocations/day
• Keeps the server within Supabase free tier limits
• No functional change to tool behavior

🤖 Generated with Claude Code

[github-actions]

Hey @Promithius-DR — welcome to Open Brain Source! 👋

Thanks for submitting your first PR. The automated review will run shortly and check things like metadata, folder structure, and README completeness. If anything needs fixing, the review comment will tell you exactly what.

Once the automated checks pass, a human admin will review for quality and clarity. Expect a response within a few days.

If you have questions, check out CONTRIBUTING.md or open an issue.