fix: prevent crash when filter menu content is empty

- Changed OR (||) to AND (&&) in FeedInfo.isValid()
- Prevents index out of range crash when items array is empty
- Fixes crash reported in TestFlight feedback

Crash details:
- Swift runtime failure: Index out of range
- Location: FeedInfo.isValid() accessing items[0] on empty array
- Trigger: Filter menu with no corresponding content

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: graycreate

V2er/State/DataFlow/Model/FeedInfo.swift

@@ -25,7 +25,7 @@ struct FeedInfo: BaseModel {
         if twoStepStr.notEmpty() && twoStepStr.contains("两步验证") {
             return false
         }
-        return items.count > 0 || items[0].userName.notEmpty
+        return items.count > 0 && items[0].userName.notEmpty
     }
 
     mutating func append(feedInfo: FeedInfo) {