feat: Flag mixing up "the latter" and "the later"

"The latter" would be an entire invariable noun phrase and is usually contrasted with "the former". "The later" normally needs to be followed by a nominal.

**Found examples:**
- The number of questions opened is meaningless, while the **later** is simply a tag and thus redundant.
- I'm glad in my journey I discover UIKit, love NSConstraint (all in swift) than moved to flutter and web **latter**.

No source file, test, or entry point is named. Start by locating the Rust grammar-checker rule or tests handling “latter” and “later,” then compare them with the two reported examples. Done means the incorrect usages are flagged while valid contrasts between “the former” and “the latter” remain accepted.

Written by the indexing model from the issue text.