Add multiplayer bots, typing languages, and rework the UI layout

Multiplayer
- Quick match: POST /api/multiplayer/quickmatch returns whichever room is
  still filling, or opens one. Players never see a room code; joining by
  code stays for racing specific people.
- Bots fill quick-match rooms after a short wait so a new game is never an
  empty lobby. They only ever join quick-match rooms, never a room opened
  by code. One or two per room, drawn from separate ~40 and ~80 WPM tiers so
  two bots are never near each other's pace, and they stall to correct
  mistakes rather than typing a clean straight line.
- Live player count via GET /api/multiplayer/online, shown on the
  Multiplayer control and under the main menu's Multiplayer button.
- Per-racer colours: you are the theme accent, opponents take distinct hues
  that stay the same from lobby to race.
- The countdown no longer holds the room lock for its full three seconds,
  which is what reset clients mid-countdown.

Typing languages
- 16 languages for the generated-word modes, each with its own
  high-frequency vocabulary rather than a translation of the English list.
- Picker in the top-right rail; non-English uses its own list at every
  difficulty tier instead of falling back to English words.

Fix UTF-8 accuracy in the game core
- update_game_state mixed byte and character counts: total_characters_typed
  accumulated byte-length deltas while total_correct_characters compared a
  char index against that byte count. Equal on ASCII, so it went unnoticed;
  a correctly typed Spanish passage scored 6%. The old byte slicing would
  also have panicked if an index landed inside a multi-byte character.
  Rewritten char-based, with regression tests.

Programming mode
- Replaced prose about programming with real code: 26 syntax-highlighted
  snippets across JavaScript, Python, Rust, C/Go/Java and shell. Single-line
  by necessity, since the typing input is a single-line field.

Layout and readability
- One icon rail arrangement on every screen: Settings/Store under the
  wordmark, Language/Theme/Friends/Account top-right, Stats/Leaderboard/
  Multiplayer bottom-right.
- Main menu: mode picker moved out of the Single Player button, which it was
  notching a divider through and pushing the label off-centre.
- Escape returns to the menu, closing any open popover first, and confirms
  before abandoning a live race.
- Split --text-color and --sub-color per theme; they shared one value that
  measured 3.65:1 against the background, below the 4.5:1 body-text floor.
- Semantic colours used in exactly one place each: gold for a personal best,
  amber for the race countdown and the mobile-result badge.
- Passage now sits in the same place on the typing and end screens, and its
  column is a whole number of characters wide so wrapping cannot leave a
  permanent gap on the right.
- End screen: keystrokes and a correct/wrong/extra/missed split, attribution
  carried over from the typing screen, and a graph with a separate error
  axis, axis titles including seconds, and smoothed lines.

1 files changed, 0 insertions, 164 deletions

diff --git a/src/test.rs b/src/test.rs
deleted file mode 100644
index 7f2728e..0000000
--- a/src/test.rs
+++ /dev/null
@@ -1,164 +0,0 @@
-// Import necessary items for testing
-use crate::{draw_typing_game, input_handler, read_sentences, App, State};
-use crossterm::event::{KeyCode, KeyEvent};
-use std::{
-    io,
-    sync::{Arc, Mutex},
-};
-use tui::layout::Rect;
-use tui::{backend::CrosstermBackend, Terminal};
-
-#[cfg(test)]
-#[allow(unused_imports)] // Ignore unused import warnings within the test module
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_new_app() {
-        // Test that a new App initializes correctly
-        let app_result = App::new();
-        assert!(app_result.is_ok());
-        let app = app_result.unwrap();
-        assert_eq!(app.input_string, "");
-        assert_eq!(app.time_taken, 0);
-        assert_eq!(app.timer, None);
-        assert_eq!(app.state, State::MainMenu);
-        assert_eq!(app.should_exit, false);
-        assert!(!app.sentences.is_empty());
-        assert!(app.current_sentence_index < app.sentences.len());
-    }
-
-    #[test]
-    fn test_reset_app() {
-        // Test the reset functionality of App
-        let mut app = App::new().unwrap();
-        app.current_sentence_index = 0; // Set initial index to 0
-        let old_index = app.current_sentence_index;
-        println!(
-            "Before reset: old_index = {}, current_sentence_index = {}",
-            old_index, app.current_sentence_index
-        );
-
-        app.time_taken = 100;
-        app.input_string = "Some input".to_string();
-        app.reset();
-
-        println!(
-            "After reset: old_index = {}, current_sentence_index = {}",
-            old_index, app.current_sentence_index
-        );
-
-        // Check that current_sentence_index changes after reset
-        assert_ne!(app.current_sentence_index, old_index);
-        assert_eq!(app.time_taken, 0);
-        assert_eq!(app.input_string, "");
-        assert_eq!(app.timer, None);
-        assert_eq!(app.state, State::TypingGame);
-    }
-
-    #[test]
-    fn test_current_sentence() {
-        // Test the retrieval of the current sentence
-        let app = App::new().unwrap();
-        let current_sentence = app.current_sentence();
-        assert!(!current_sentence.is_empty());
-    }
-
-    #[test]
-    fn test_start_timer() {
-        // Test starting the timer
-        let mut app = App::new().unwrap();
-        app.start_timer();
-        assert!(app.timer.is_some());
-    }
-
-    #[test]
-    fn test_update_timer() {
-        // Test updating the timer
-        let mut app = App::new().unwrap();
-        app.start_timer();
-        let initial_time = app.time_taken;
-        std::thread::sleep(std::time::Duration::from_secs(1));
-        app.update_timer();
-        assert!(app.time_taken > initial_time);
-    }
-
-    #[test]
-    fn test_update_wpm() {
-        // Test updating words per minute calculation
-        let mut app = App::new().unwrap();
-        app.time_taken = 60; // 1 minute
-        app.input_string = "This is a test sentence".to_string();
-        let wpm = app.update_wpm();
-        assert_eq!(wpm, 5.0); // 5 words per minute for this sentence
-    }
-
-    #[test]
-    fn test_read_sentences() {
-        // Test reading sentences from a file
-        let sentences_result = read_sentences("sentences.txt");
-        assert!(sentences_result.is_ok());
-        let sentences = sentences_result.unwrap();
-        assert!(!sentences.is_empty());
-    }
-
-    #[test]
-    fn test_draw_typing_game() {
-        // Test drawing the typing game UI
-        let mut app = App::new().unwrap();
-        let stdout = io::stdout();
-        let backend = CrosstermBackend::new(stdout);
-        let mut terminal = Terminal::new(backend).unwrap();
-        let size = Rect::default();
-        draw_typing_game(&mut terminal.get_frame(), size, &mut app);
-        // No need to assert anything here since it's a rendering function
-    }
-
-    #[tokio::test]
-    async fn test_input_handler() {
-        // Test the input handler function
-        let mut app = App::new().unwrap();
-
-        // Simulate typing 'a'
-        let event = KeyEvent::from(KeyCode::Char('a'));
-        input_handler(event, &mut app, Arc::new(Mutex::new(()))).await;
-        assert_eq!(app.input_string, "a");
-
-        // Simulate typing 'b'
-        let event = KeyEvent::from(KeyCode::Char('b'));
-        input_handler(event, &mut app, Arc::new(Mutex::new(()))).await;
-        assert_eq!(app.input_string, "ab");
-
-        // Simulate pressing Backspace
-        let event = KeyEvent::from(KeyCode::Backspace);
-        input_handler(event, &mut app, Arc::new(Mutex::new(()))).await;
-        assert_eq!(app.input_string, "a");
-
-        // Simulate pressing Enter in MainMenu state
-        let event = KeyEvent::from(KeyCode::Enter);
-        app.state = State::MainMenu;
-        input_handler(event, &mut app, Arc::new(Mutex::new(()))).await;
-        assert_eq!(app.state, State::TypingGame);
-        assert_eq!(app.input_string, "");
-
-        // Simulate typing 'T' in TypingGame state
-        let event = KeyEvent::from(KeyCode::Char('T'));
-        app.state = State::TypingGame;
-        input_handler(event, &mut app, Arc::new(Mutex::new(()))).await;
-        assert_eq!(app.input_string, "T");
-
-        // Simulate completing sentence and pressing Enter
-        let sentence = app.current_sentence().to_string();
-        app.input_string = sentence.clone();
-        let event = KeyEvent::from(KeyCode::Enter);
-        input_handler(event, &mut app, Arc::new(Mutex::new(()))).await;
-        assert_eq!(app.state, State::EndScreen);
-        assert_eq!(app.input_string.trim(), sentence.trim());
-
-        // Simulate pressing Esc in EndScreen state
-        let event = KeyEvent::from(KeyCode::Esc);
-        app.state = State::EndScreen;
-        input_handler(event, &mut app, Arc::new(Mutex::new(()))).await;
-        assert_eq!(app.should_exit, true);
-    }
-}