term: Remove dependency on libc

Introducing the new enum `TerminalFile` to model which standard stream
stream the terminal uses allows us to remove the dependency on `libc`
which does not build on Windows.

Cargo.lock

@@ -2787,7 +2787,6 @@ dependencies = [
  "crossterm 0.29.0",
  "git2",
  "inquire",
- "libc",
  "pretty_assertions",
  "radicle-signals",
  "shlex",

crates/radicle-remote-helper/src/lib.rs

@@ -90,7 +90,7 @@ pub struct Options {
 pub fn run(profile: radicle::Profile) -> Result<(), Error> {
     // Since we're going to be writing user output to `stderr`, make sure the paint
     // module is aware of that.
-    cli::Paint::set_terminal(io::stderr());
+    cli::Paint::set_terminal(cli::TerminalFile::Stderr);
 
     let (remote, url): (Option<git::RefString>, Url) = {
         let args = env::args().skip(1).take(2).collect::<Vec<_>>();

crates/radicle-term/Cargo.toml

@@ -17,7 +17,6 @@ anyhow = { workspace = true }
 anstyle-query = "1.0.0"
 crossterm = "0.29.0"
 inquire = { version = "0.7.4", default-features = false, features = ["crossterm", "editor"] }
-libc = { workspace = true }
 shlex = { workspace = true }
 thiserror = { workspace = true }
 unicode-display-width = "0.3.0"

crates/radicle-term/src/ansi.rs

@@ -13,4 +13,5 @@ pub use color::Color;
 pub use paint::paint;
 pub use paint::Filled;
 pub use paint::Paint;
+pub use paint::TerminalFile;
 pub use style::Style;

crates/radicle-term/src/ansi/paint.rs

@@ -1,5 +1,4 @@
 use std::io::IsTerminal as _;
-use std::os::fd::{AsRawFd, BorrowedFd};
 use std::sync::atomic::{AtomicBool, AtomicI32};
 use std::sync::LazyLock;
 use std::{fmt, sync};
@@ -7,8 +6,36 @@ use std::{fmt, sync};
 use super::color::Color;
 use super::style::{Property, Style};
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[repr(i32)]
+pub enum TerminalFile {
+    Stdout = 1,
+    Stderr = 2,
+}
+
+impl TryFrom<i32> for TerminalFile {
+    type Error = ();
+
+    fn try_from(value: i32) -> Result<Self, Self::Error> {
+        match value {
+            1 => Ok(TerminalFile::Stdout),
+            2 => Ok(TerminalFile::Stderr),
+            _ => Err(()),
+        }
+    }
+}
+
+impl TerminalFile {
+    fn is_terminal(&self) -> bool {
+        match self {
+            TerminalFile::Stdout => std::io::stdout().is_terminal(),
+            TerminalFile::Stderr => std::io::stderr().is_terminal(),
+        }
+    }
+}
+
 /// What file is used for text output.
-static TERMINAL: AtomicI32 = AtomicI32::new(libc::STDOUT_FILENO);
+static TERMINAL: AtomicI32 = AtomicI32::new(TerminalFile::Stdout as i32);
 /// Whether paint styling is enabled or not.
 static ENABLED: AtomicBool = AtomicBool::new(true);
 /// Whether paint styling should be forced.
@@ -263,7 +290,7 @@ impl Paint<()> {
         let clicolor_enabled = clicolor.unwrap_or(false);
         let clicolor_disabled = !clicolor.unwrap_or(true);
         let terminal = TERMINAL.load(sync::atomic::Ordering::SeqCst);
-        let is_terminal = unsafe { BorrowedFd::borrow_raw(terminal).is_terminal() };
+        let is_terminal = TerminalFile::try_from(terminal).is_ok_and(|tf| tf.is_terminal());
         let is_enabled = ENABLED.load(sync::atomic::Ordering::SeqCst);
 
         is_terminal
@@ -287,8 +314,8 @@ impl Paint<()> {
 
     /// Set the terminal we are writing to. This influences the logic that checks whether or not to
     /// include colors.
-    pub fn set_terminal(fd: impl AsRawFd) {
+    pub fn set_terminal(tf: TerminalFile) {
-        TERMINAL.store(fd.as_raw_fd(), sync::atomic::Ordering::SeqCst);
+        TERMINAL.store(tf as i32, sync::atomic::Ordering::SeqCst);
     }
 
     /// Force paint styling.

crates/radicle-term/src/lib.rs

@@ -17,7 +17,7 @@ use std::fmt;
 use std::io::IsTerminal;
 
 pub use ansi::Color;
-pub use ansi::{paint, Filled, Paint, Style};
+pub use ansi::{paint, Filled, Paint, Style, TerminalFile};
 pub use editor::Editor;
 pub use element::{Constraint, Element, Line, Size};
 pub use hstack::HStack;