fix(wasm): fix browser input and runtime exit handling

Use ev.key directly to preserve Caps Lock casing, implement clipboard
paste, and prevent :q/:qa from leaving the runtime in a loop.

src/wasm/app.js

@@ -295,7 +295,7 @@ function translateKey(ev) {
   };
   if (named[ev.key]) return named[ev.key];
   if (ev.key.length === 1) {
-    let char = ev.shiftKey ? ev.key : ev.key.toLowerCase();
+    let char = ev.key;
     if (char === "<") char = "<lt>";
     if (!isCtrl && !isAlt) return char;
     let mod = "";
@@ -368,13 +368,22 @@ function main() {
       }
     }
   });
-
+  transport.onExit((code) => {
+      setStatus(`Neovim exited (code ${code}). Refresh the page to start a new session.`);
+      gridEl.style.opacity = "0.5";
+    });
   nvim.on("redraw", (params) =>
     handleRedrawEvents(uiState, gridEl, modeEl, params),
   );
 
   gridEl.addEventListener("click", () => gridEl.focus());
   gridEl.addEventListener("keydown", (ev) => {
+    const isPasteShortcut =
+      (ev.ctrlKey && ev.shiftKey && ev.key.toLowerCase() === "v") || // Linux/Win: Ctrl+Shift+V
+      (ev.metaKey && ev.key.toLowerCase() === "v");                  // macOS: Cmd+V
+    if (isPasteShortcut) {
+      return;
+    }
     const keys = translateKey(ev);
     if (!keys) return;
     ev.preventDefault();
@@ -382,6 +391,15 @@ function main() {
       .request("nvim_input", [keys])
       .catch((e) => console.error("nvim_input failed", e));
   });
+  gridEl.addEventListener("paste", (ev) => {
+    ev.preventDefault();
+    const text = ev.clipboardData.getData("text/plain");
+    if (!text) return;
+    nvim
+      .request("nvim_paste", [text, true, -1])
+      .catch((e) => console.error("paste nvim_input failed", e));
+  });
+
 }
 
 if (!crossOriginIsolated) {

src/wasm/nvim-worker.js

@@ -511,7 +511,7 @@ self.onmessage = async (ev) => {
       );
     };
 
-    const { argc, argv } = makeArgv(m, ["nvim", "--embed", "--clean"]);
+    const { argc, argv } = makeArgv(m, ["nvim", "--embed"]);
 
     let ret;
 
@@ -535,14 +535,38 @@ self.onmessage = async (ev) => {
       ret = await nvimPromise;
 
       console.log("NVIM EXITED");
+      postMessage({ type: "exited", code: ret });
+      try {
+        moduleRef.ccall("emscripten_force_exit", null, ["number"], [ret]);
+      } catch (e) {
+        safeStatus("force_exit failed: " + e);
+      }
       const unread = unreadCount();
       safeStatus(
         `_nvim_main RETURNED ret=${ret}, unread bytes still in buffer=${unread}`,
       );
     } catch (e) {
+          console.log('CAUGHT EXIT EXCEPTION', e, 'name=', e && e.name, 'status=', e && e.status, 'constructor=', e && e.constructor && e.constructor.name);
+
       flushAll();
-      safeStatus("EXCEPTION: " + e.message + "\nSTACK:\n" + e.stack);
-      throw e;
+    if (e && e.name === 'ExitStatus') {
+        safeStatus(`Neovim exited cleanly, code=${e.status}`);
+        ret = e.status;
+    
+    // Notify app.js so it can show a session ended state instead of
+    // leaving the UI looking frozen.
+    postMessage({ type: "exited", code: ret });
+    try {
+          moduleRef.ccall("emscripten_force_exit", null, ["number"], [ret]);
+        } catch (fe) {
+          safeStatus("force_exit failed: " + fe);
+        }
+      }
+    else 
+      {
+        safeStatus('EXCEPTION: ' + e.message + '\nSTACK:\n' + e.stack);
+        throw e;
+    }
     }
 
     flushAll();

src/wasm/rpc.js

@@ -10,6 +10,7 @@ class WorkerTransport {
     this._bytesHandlers = [];
     this._statusHandlers = [];
     this._readyHandlers = [];
+    this._exitHandlers = [];
 
     this.worker = new Worker(workerPath);
     this.worker.onmessage = (ev) => {
@@ -48,6 +49,10 @@ class WorkerTransport {
       console.log("[main] worker signaled ready, RPC channel should be live");
       this._readyHandlers.forEach((h) => h());
     }
+    else if (msg.type === "exited") {
+      console.log("worker signaled nvim exited, code=", msg.code);
+      this._exitHandlers.forEach((h) => h(msg.code));
+    }
   }
 
   _emitStatus(text) {
@@ -123,6 +128,9 @@ class WorkerTransport {
   onReady(cb) {
     this._readyHandlers.push(cb);
   }
+  onExit(cb) {
+    this._exitHandlers.push(cb);
+  }
   persist() {
     this.worker.postMessage({ type: "persist" });
   }