fix(node): scope raw descriptor adoption

[nathanwhit]

Summary

• distinguish isolate-registered descriptors from untracked process descriptors
• register pipe and child-process descriptors before handing them to Node stream wrappers
• preserve stdio, inherited extra-stdio, and fully-authorized raw descriptor compatibility

Details

TCPWrap.open() and PipeWrap.open() previously treated any untracked OS descriptor as available for adoption. The OS descriptor table is process-wide, while Deno's descriptor tracking is isolate-local, so an untracked number may belong to a different isolate.

This change adds an explicit adoptable state for descriptors produced for the current isolate. Unknown non-stdio descriptors are rejected unless the isolate has all permissions, preserving the existing raw-descriptor compatibility path for fully-authorized programs. Successful adoption remains one-time.

Validation

• cargo build -p deno --bin deno
• cargo test -p deno_io fd_table --lib
• cargo test -p deno_node --lib
• cargo test -p deno_process --lib
• cargo test -p specs_tests --test specs -- specs::node::pipe_open_fd
• cargo test -p specs_tests --test specs -- specs::node::net_socket_fd::tcp_open
• cargo test -p unit_node_tests --test unit_node -- unit_node::child_process_test
• ./tools/format.js --check