Improve error message for server.accept() failures

Enhanced the error message to include:
- The actual file descriptor number that failed
- Guidance on common failure causes (invalid socket FD, SSL mismatch)

This helps users diagnose issues more quickly when accept() fails.

Addresses CodeRabbit review comment.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/bun.js/api/server.zig

@@ -1835,7 +1835,7 @@ pub fn NewServer(protocol_enum: enum { http, https }, development_kind: enum { d
 
             const result = app.accept(bun.FileDescriptor.fromUV(@intCast(fd)));
             if (result != 0) {
-                return globalThis.throwInvalidArguments("Failed to accept file descriptor", .{});
+                return globalThis.throwInvalidArguments("Failed to accept file descriptor {d}. Ensure it is a valid socket file descriptor and matches the server's SSL configuration.", .{fd});
             }
 
             return .js_undefined;