fix: address Qodo code review findings

- Add missing snapshot-differ.test.ts to npm test script
- Fix path traversal vulnerability in agent-mail.ts with message ID validation
- Fix readLastTouchedVersion to log errors instead of silently swallowing them
- Sanitize log statements to not leak full paths
- Add projectRoot validation to all API routes
- Fix activity persistence write race conditions with promise chaining

Co-authored-by: openhands <openhands@all-hands.dev>

src/lib/agent-mail.ts

@@ -98,6 +98,12 @@ function trimOrEmpty(value: unknown): string {
   return typeof value === 'string' ? value.trim() : '';
 }
 
+function isValidMessageId(value: string): boolean {
+  // Message IDs must be alphanumeric with underscores, hyphens, and colons
+  // This prevents path traversal attacks
+  return /^[a-zA-Z0-9_\-:]+$/.test(value);
+}
+
 function success<T>(command: MailCommandName, data: T): MailCommandResponse<T> {
   return {
     ok: true,
@@ -330,6 +336,10 @@ export async function readAgentMessage(
     return invalid(command, 'MESSAGE_NOT_FOUND', 'Message id is required.');
   }
 
+  if (!isValidMessageId(messageId)) {
+    return invalid(command, 'INVALID_MESSAGE_ID', 'Message id contains invalid characters.');
+  }
+
   try {
     const existing = await readMessageIndex(messageId);
     if (!existing) {
@@ -374,6 +384,10 @@ export async function ackAgentMessage(
     return invalid(command, 'MESSAGE_NOT_FOUND', 'Message id is required.');
   }
 
+  if (!isValidMessageId(messageId)) {
+    return invalid(command, 'INVALID_MESSAGE_ID', 'Message id contains invalid characters.');
+  }
+
   try {
     const existing = await readMessageIndex(messageId);
     if (!existing) {

src/lib/realtime.ts

@@ -38,7 +38,7 @@ export class IssuesEventBus {
   private nextSubscriberId = 1;
 
   emit(projectRoot: string, changedPath?: string, kind: IssuesChangeKind = 'changed'): IssuesChangedEvent {
-    console.log(`[IssuesBus] Emitting event: ${kind} for ${projectRoot} (${changedPath})`);
+    console.log(`[IssuesBus] Emitting event: ${kind} for project (${changedPath ? path.basename(changedPath) : 'unknown'})`);
     const canonicalProjectRoot = canonicalizeWindowsPath(projectRoot);
     const projectKey = windowsPathKey(canonicalProjectRoot);
     const event: IssuesChangedEvent = {
@@ -94,6 +94,7 @@ export class ActivityEventBus {
   private readonly history: ActivityEvent[] = [];
   private readonly MAX_HISTORY = 100;
   private initialized = false;
+  private savePromise: Promise<void> | null = null;
 
   private nextSubscriberId = 1;
 
@@ -121,8 +122,22 @@ export class ActivityEventBus {
       this.history.pop();
     }
 
-    // Persist async
-    void saveActivityHistory(this.history);
+    // Persist async with deduplication - wait for any pending save to complete
+    const currentHistory = [...this.history];
+    const persist = async () => {
+      try {
+        await saveActivityHistory(currentHistory);
+      } catch (error) {
+        console.error('[ActivityEventBus] Failed to save history:', error);
+      }
+    };
+    
+    if (this.savePromise === null) {
+      this.savePromise = persist();
+    } else {
+      // Chain to existing promise to prevent concurrent writes
+      this.savePromise = this.savePromise.then(persist);
+    }
 
     for (const subscriber of this.subscribers.values()) {
       if (!subscriber.projectKey || subscriber.projectKey === projectKey) {