fix: address code review findings across WS, CJK input, install.sh, and README

WebSocket route: add socket error handler to prevent process crashes, enforce
per-session connection limit (max 5), track/decrement counts on close.

CJK input: add destroy() method with proper listener cleanup, guard against
double-init, add maxlength/aria-label to textarea, use language-neutral
placeholder, explicitly clear cjkActive on hide.

install.sh: fix update() to use $BRANCH and $REPO_URL instead of hardcoded
origin/master — fork users were silently switched back to master on update.

README: fix broken markdown table (paragraph concatenated into last cell),
add CODEMAN_NODE_VERSION to env var table.

Tests: add 8 new test cases for batch coalescing, flush threshold, unknown
message types, connection limit, heartbeat, readyState guards. Import
MAX_INPUT_LENGTH from config, add connectWs timeout, replace setTimeout
with vi.waitFor in cleanup test.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/web/public/app.js

@@ -3083,7 +3083,10 @@ class CodemanApp {
 
     // CJK input form: show/hide based on server env INPUT_CJK_FORM=ON
     const cjkEl = document.getElementById('cjkInput');
-    if (cjkEl) cjkEl.style.display = data.inputCjkForm ? 'block' : 'none';
+    if (cjkEl) {
+      cjkEl.style.display = data.inputCjkForm ? 'block' : 'none';
+      if (!data.inputCjkForm) window.cjkActive = false;
+    }
 
     // Update version displays (header and toolbar)
     if (data.version) {

src/web/public/index.html

@@ -233,7 +233,8 @@
     <main class="main">
       <div class="terminal-wrap">
         <div class="terminal-container" id="terminalContainer"></div>
-        <textarea id="cjkInput" rows="1" placeholder="CJK 입력 → Enter 전송 / ESC 취소"
+        <textarea id="cjkInput" rows="1" placeholder="CJK input (Enter = send, Esc = clear)"
+          maxlength="65536" aria-label="CJK IME input field"
           autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false"></textarea>
       </div>
 

src/web/public/input-cjk.js

@@ -7,14 +7,20 @@
  * While this textarea has focus, window.cjkActive = true blocks xterm's onData.
  * Arrow keys and function keys are forwarded to PTY directly.
  *
- * @globals {object} CjkInput
- * @loadorder 5.5 of 9 — loaded after keyboard-accessory.js, before app.js
+ * @dependency index.html (#cjkInput textarea)
+ * @globals {object} CjkInput — window.cjkActive (boolean) signals app.js to block xterm onData
+ * @loadorder 5.5 of 10 — loaded after keyboard-accessory.js, before app.js
  */
 
 // eslint-disable-next-line no-unused-vars
 const CjkInput = (() => {
   let _textarea = null;
   let _send = null;
+  let _initialized = false;
+  let _onMousedown = null;
+  let _onFocus = null;
+  let _onBlur = null;
+  let _onKeydown = null;
 
   const PASSTHROUGH_KEYS = {
     ArrowUp:    '\x1b[A',
@@ -32,15 +38,21 @@ const CjkInput = (() => {
 
   return {
     init({ send }) {
+      // Guard against double-init: remove previous listeners
+      if (_initialized) this.destroy();
+
       _send = send;
       _textarea = document.getElementById('cjkInput');
       if (!_textarea) return this;
 
-      _textarea.addEventListener('mousedown', (e) => { e.stopPropagation(); });
-      _textarea.addEventListener('focus', () => { window.cjkActive = true; });
-      _textarea.addEventListener('blur', () => { window.cjkActive = false; });
+      _onMousedown = (e) => { e.stopPropagation(); };
+      _onFocus = () => { window.cjkActive = true; };
+      _onBlur = () => { window.cjkActive = false; };
+      _textarea.addEventListener('mousedown', _onMousedown);
+      _textarea.addEventListener('focus', _onFocus);
+      _textarea.addEventListener('blur', _onBlur);
 
-      _textarea.addEventListener('keydown', (e) => {
+      _onKeydown = (e) => {
         if (e.isComposing || e.keyCode === 229) return;
 
         // Enter: send accumulated text (or bare Enter if empty)
@@ -82,11 +94,25 @@ const CjkInput = (() => {
           _send(PASSTHROUGH_KEYS[e.key]);
           return;
         }
-      });
+      };
+      _textarea.addEventListener('keydown', _onKeydown);
 
+      _initialized = true;
       return this;
     },
 
+    destroy() {
+      if (_textarea) {
+        if (_onMousedown) _textarea.removeEventListener('mousedown', _onMousedown);
+        if (_onFocus) _textarea.removeEventListener('focus', _onFocus);
+        if (_onBlur) _textarea.removeEventListener('blur', _onBlur);
+        if (_onKeydown) _textarea.removeEventListener('keydown', _onKeydown);
+      }
+      window.cjkActive = false;
+      _onMousedown = _onFocus = _onBlur = _onKeydown = null;
+      _initialized = false;
+    },
+
     get element() { return _textarea; },
   };
 })();