fix: terminal command execution via HTTP POST workaround

The WebSocket send mechanism fails with close code 1006 when client
tries to send data to server. Server never receives the message,
indicating a network/proxy layer issue that couldn't be fixed through
code changes or nginx configuration.

Solution: Bypass WebSocket send entirely by using HTTP POST to send
commands directly to the PTY.

Changes:
- Added sendTerminalInput() method to terminal-service.js that writes
  directly to PTY, bypassing WebSocket
- Added POST endpoint /claude/api/terminals/:id/input to server.js
- Modified launchCommand() in terminal.js to use fetch() with HTTP
  POST instead of WebSocket.send()

The WebSocket receive direction still works (server→client for output
display), only send direction (client→server for commands) is bypassed.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

public/claude-ide/terminal.js

@@ -683,7 +683,7 @@ class TerminalManager {
 
   /**
    * Launch a command in the terminal
-   * Waits for terminal to be ready before sending command
+   * Uses HTTP POST as workaround for WebSocket send issue
    */
   async launchCommand(terminalId, command) {
     this.debugLog('CMD', `launchCommand called: terminalId=${terminalId}, command="${command.trim()}"`);
@@ -700,44 +700,30 @@ class TerminalManager {
 
     this.debugLog('CMD', `Terminal ${terminalId} is ready!`);
 
-    // NO DELAY - send command immediately to avoid WebSocket closure
-    this.debugLog('CMD', `Sending command immediately without delay...`);
-
-    const terminal = this.terminals.get(terminalId);
-    if (!terminal) {
-      this.debugLog('ERROR', `Terminal ${terminalId} not found in map`);
-      return;
-    }
-
-    if (!terminal.ws) {
-      this.debugLog('ERROR', `WebSocket not set for terminal ${terminalId}`);
-      return;
-    }
-
-    // Check WebSocket state
-    const readyStates = ['CONNECTING', 'OPEN', 'CLOSING', 'CLOSED'];
-    this.debugLog('CMD', `WebSocket state: ${readyStates[terminal.ws.readyState]} (${terminal.ws.readyState})`);
-
-    if (terminal.ws.readyState !== WebSocket.OPEN) {
-      this.debugLog('ERROR', `Cannot send - WebSocket not open`, {
-        wsState: terminal.ws.readyState,
-        stateName: readyStates[terminal.ws.readyState]
-      });
-      return;
-    }
-
-    // Send command to terminal immediately
-    const message = JSON.stringify({
-      type: 'input',
-      data: command
-    });
-    this.debugLog('CMD', `Sending to WebSocket: ${message}`);
+    // Use HTTP POST instead of WebSocket send (bypasses proxy issue)
+    this.debugLog('CMD', `Sending command via HTTP POST: ${command.trim()}`);
 
     try {
-      terminal.ws.send(message);
-      this.debugLog('CMD', `Command sent to terminal ${terminalId}: ${command.trim()}`);
+      const res = await fetch(`/claude/api/terminals/${terminalId}/input`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ data: command })
+      });
+
+      if (!res.ok) {
+        throw new Error(`HTTP ${res.status}: ${res.statusText}`);
+      }
+
+      const result = await res.json();
+
+      if (result.success) {
+        this.debugLog('CMD', `Command sent to terminal ${terminalId} via HTTP: ${command.trim()}`);
+      } else {
+        this.debugLog('ERROR', `Failed to send command: ${result.error}`);
+        showToast(`Failed to send command: ${result.error}`, 'error');
+      }
     } catch (error) {
-      this.debugLog('ERROR', `Failed to send command`, { error: error.message, name: error.name });
+      this.debugLog('ERROR', `HTTP POST failed:`, { error: error.message });
       showToast(`Failed to send command: ${error.message}`, 'error');
     }
   }