refactor: reorder postMessageProcessing parameters for clarity

Rearrange the `postMessageProcessing` signature so that `isProactiveMode` now precedes the internal `currentStepCount`.
This change improves the logical flow of the API: the proactive flag is a public flag that callers should set, whereas the step counter is an internal bookkeeping value. The updated order also aligns the JSDoc comment with the implementation.

All related tests were updated to reflect the new parameter order, and comments were adjusted to describe the internal counter in the correct place. No functional behavior changes occur; the change simply makes the API easier to read and maintain.

web-app/src/lib/__tests__/completion.test.ts

@@ -673,7 +673,6 @@ describe('completion.ts', () => {
         [], // tools
         undefined, // updateStreamingUI
         undefined, // maxToolSteps
-        undefined, // currentStepCount
         true // isProactiveMode - Correctly set to true
       )
 
@@ -733,7 +732,6 @@ describe('completion.ts', () => {
         [], // tools
         undefined, // updateStreamingUI
         undefined, // maxToolSteps
-        undefined, // currentStepCount
         false // isProactiveMode - Correctly set to false
       )
 
@@ -788,7 +786,6 @@ describe('completion.ts', () => {
         [], // tools
         undefined, // updateStreamingUI
         undefined, // maxToolSteps
-        undefined, // currentStepCount
         true // isProactiveMode - Still set to true, but the non-browser tool should skip the proactive step
       )
 

web-app/src/lib/completion.ts

@@ -534,8 +534,8 @@ const filterOldProactiveScreenshots = (builder: CompletionMessagesBuilder) => {
  * @param tools
  * @param updateStreamingUI
  * @param maxToolSteps
- * @param currentStepCount - Internal counter for recursive calls (do not set manually)
  * @param isProactiveMode
+ * @param currentStepCount - Internal counter for recursive calls (do not set manually)
  */
 export const postMessageProcessing = async (
   calls: ChatCompletionMessageToolCall[],
@@ -554,8 +554,8 @@ export const postMessageProcessing = async (
   tools: MCPTool[] = [],
   updateStreamingUI?: (content: ThreadMessage) => void,
   maxToolSteps: number = 20,
-  currentStepCount: number = 0,
+  isProactiveMode: boolean = false,
-  isProactiveMode: boolean = false
+  currentStepCount: number = 0
 ): Promise<ThreadMessage> => {
   // Initialize/get the current total thinking time from metadata
   // This value is passed from sendMessage (initial completion time) or previous recursive call
@@ -877,8 +877,8 @@ export const postMessageProcessing = async (
               tools,
               updateStreamingUI,
               maxToolSteps,
+              isProactiveMode,
               nextStepCount, // Pass the incremented step count
-              isProactiveMode
             )
           }
         }