fix: generate new UUID on session reset to force new session file

Previously resetSession() set currentSessionId=null, but run.mjs
treated null as "find most recent session", continuing old conversation.
Now generates a fresh UUID so run.mjs creates a new session file.

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

Author: k-l-lambda

app/src/main/java/com/anthroid/claude/OpenClawLocalClient.kt

@@ -401,8 +401,8 @@ class OpenClawLocalClient(private val context: Context) {
      */
     /** Reset session ID to start a fresh conversation. */
     fun resetSession() {
-        currentSessionId = null
-        Log.i(TAG, "Session reset — next chat will create a new session")
+        currentSessionId = java.util.UUID.randomUUID().toString()
+        Log.i(TAG, "Session reset — new session ID: $currentSessionId")
     }
 
     fun cancelCurrentRequest() {