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, 162 insertions, 0 deletions

diff --git a/crates/wasm/src/lib.rs b/crates/wasm/src/lib.rs
new file mode 100644
index 0000000..abec93b
--- /dev/null
+++ b/crates/wasm/src/lib.rs
@@ -0,0 +1,162 @@
+use wasm_bindgen::prelude::*;
+use typerpunk_core::game::Game;
+
+// Re-export TyperPunkGame as TyperPunk
+pub use typerpunk_core::wasm::TyperPunkGame as TyperPunk;
+
+#[wasm_bindgen]
+pub struct TyperPunkGame {
+    game: Option<Game>,
+}
+
+#[wasm_bindgen]
+impl TyperPunkGame {
+    #[wasm_bindgen(constructor)]
+    pub fn new() -> Self {
+        Self {
+            game: Some(Game::new()),
+        }
+    }
+
+    #[wasm_bindgen]
+    pub fn set_text(&mut self, text: &str) -> Result<(), JsValue> {
+        let game = self.game.as_mut()
+            .ok_or_else(|| JsValue::from_str("Game not initialized"))?;
+
+        // Create a new owned string and validate UTF-8
+        let text_str = match std::str::from_utf8(text.as_bytes()) {
+            Ok(s) => s.to_string(),
+            Err(_) => return Err(JsValue::from_str("Invalid UTF-8 text")),
+        };
+
+        game.set_text(text_str);
+        Ok(())
+    }
+
+    #[wasm_bindgen]
+    pub fn get_text(&self) -> String {
+        self.game.as_ref()
+            .map(|game| game.get_text())
+            .unwrap_or_default()
+    }
+
+    #[wasm_bindgen]
+    pub fn get_input(&self) -> String {
+        self.game.as_ref()
+            .map(|game| game.get_input())
+            .unwrap_or_default()
+    }
+
+    #[wasm_bindgen]
+    pub fn handle_input(&mut self, input: &str) -> Result<(), JsValue> {
+        let game = self.game.as_mut()
+            .ok_or_else(|| JsValue::from_str("Game not initialized"))?;
+
+        // Create a new owned string and validate UTF-8
+        let input_str = match std::str::from_utf8(input.as_bytes()) {
+            Ok(s) => s.to_string(),
+            Err(_) => return Err(JsValue::from_str("Invalid UTF-8 input")),
+        };
+        
+        // Process input
+        game.handle_input(&input_str)
+            .map_err(|e| JsValue::from_str(&e.to_string()))
+    }
+
+    #[wasm_bindgen]
+    pub fn handle_backspace(&mut self, ctrl: bool) -> Result<bool, JsValue> {
+        let game = self.game.as_mut()
+            .ok_or_else(|| JsValue::from_str("Game not initialized"))?;
+
+        if !game.can_backspace() {
+            return Ok(false);
+        }
+
+        // Check if ctrl+backspace is allowed
+        if ctrl && !game.can_ctrl_backspace() {
+            return Ok(false);
+        }
+
+        // Perform backspace
+        game.handle_backspace(ctrl)
+            .map_err(|e| JsValue::from_str(&e.to_string()))
+    }
+
+    #[wasm_bindgen]
+    pub fn get_stats(&self) -> Result<JsValue, JsValue> {
+        let game = self.game.as_ref()
+            .ok_or_else(|| JsValue::from_str("Game not initialized"))?;
+
+        let (accuracy, mistakes) = game.get_stats()
+            .map_err(|e| JsValue::from_str(&e.to_string()))?;
+        let array = js_sys::Array::new();
+        array.push(&JsValue::from_f64(accuracy));
+        array.push(&JsValue::from_f64(mistakes as f64));
+        Ok(array.into())
+    }
+
+    #[wasm_bindgen]
+    pub fn get_stats_and_input(&self) -> Result<JsValue, JsValue> {
+        let game = self.game.as_ref()
+            .ok_or_else(|| JsValue::from_str("Game not initialized"))?;
+
+        // Get input first to avoid recursive use
+        let input = game.get_input();
+        
+        // Then get stats
+        let (_, accuracy, mistakes) = game.get_stats_and_input()
+            .map_err(|e| JsValue::from_str(&e.to_string()))?;
+        
+        let array = js_sys::Array::new();
+        array.push(&JsValue::from_str(&input));
+        array.push(&JsValue::from_f64(accuracy));
+        array.push(&JsValue::from_f64(mistakes as f64));
+        Ok(array.into())
+    }
+
+    #[wasm_bindgen]
+    pub fn is_finished(&self) -> bool {
+        // Delegates to the core Game's own is_finished() instead of a second,
+        // independent copy of the completion check - this used to
+        // re-implement the (then-current) logic by hand, which meant the
+        // exact-match-required bug fixed in core::game::Game had to be fixed
+        // here separately too, and wasn't: this copy kept requiring an exact
+        // match long after the core was fixed to be length-only, silently
+        // freezing every test with an uncorrected mistake anywhere in it.
+        self.game.as_ref()
+            .map(|game| game.is_finished())
+            .unwrap_or(false)
+    }
+
+    #[wasm_bindgen]
+    pub fn start(&mut self) {
+        if let Some(game) = &mut self.game {
+            game.start();
+        }
+    }
+
+    #[wasm_bindgen]
+    pub fn get_wpm(&self) -> f64 {
+        self.game.as_ref()
+            .map(|game| game.get_wpm())
+            .unwrap_or(0.0)
+    }
+
+    #[wasm_bindgen]
+    pub fn get_time_elapsed(&self) -> f64 {
+        self.game.as_ref()
+            .map(|game| game.get_time_elapsed())
+            .unwrap_or(0.0)
+    }
+
+    #[wasm_bindgen]
+    pub fn free(&mut self) {
+        self.game = None;
+    }
+
+}
+
+#[wasm_bindgen]
+pub fn init() {
+    console_error_panic_hook::set_once();
+} 
\ No newline at end of file