feat(chat): add CLAUDE.md support and fix scroll behavior

Add system prompt configuration to enable CLAUDE.md loading from
project, user config, and local directories. This allows Claude Code
to use custom instructions defined in CLAUDE.md files.

Fix scroll position management during message streaming to prevent
conflicting with user's manual scroll actions. Remove automatic
scroll state reset in scrollToBottom function and let scroll event
handler manage the state naturally.

Also remove debug logging for session ID capture.

server/claude-sdk.js

@@ -79,6 +79,16 @@ function mapCliOptionsToSDK(options = {}) {
   // Map model (default to sonnet)
   sdkOptions.model = options.model || 'sonnet';
 
+  // Map system prompt configuration
+  sdkOptions.systemPrompt = {
+    type: 'preset',
+    preset: 'claude_code'  // Required to use CLAUDE.md
+  };
+
+  // Map setting sources for CLAUDE.md loading
+  // This loads CLAUDE.md from project, user (~/.config/claude/CLAUDE.md), and local directories
+  sdkOptions.settingSources = ['project', 'user', 'local'];
+
   // Map resume session
   if (sessionId) {
     sdkOptions.resume = sessionId;
@@ -374,7 +384,7 @@ async function queryClaudeSDK(command, options = {}, ws) {
     for await (const message of queryInstance) {
       // Capture session ID from first message
       if (message.session_id && !capturedSessionId) {
-        console.log('📝 Captured session ID:', message.session_id);
+
         capturedSessionId = message.session_id;
         addSession(capturedSessionId, queryInstance, tempImagePaths, tempDir);