Added to top of front page
removed topic section for small screens

### 1. ActiveThreads.pm Refactoring & Dual-Column Sorting

* ** Unified Subroutine Architecture:** Consolidated logic into the `recursive_check` subroutine utilizing distinct `'reply'` and `'topic'` modes.
* ** Independent Sorting:** Enabled reliable, independent dual-column sorting for active replies versus new topics.
* ** Accurate Tracking:** Successfully populated and verified reply counts for active replies.
* ** UI Cleanup:** Added regex subject cleanup to strip repetitive leading "Re:" prefixes from displayed thread titles on the index while preserving full titles in tooltips.

### 2. Subboard Recursion & Permissions

* ** Traversal & Access Control:** Verified robust subboard traversal routines alongside strict access permission checks to ensure hidden or restricted boards stay secure.

### 3. File-Based HTML Caching & TTL Safety Net

* ** Bypassing Disk Iteration:** Replaced heavy, real-time file iteration across `$datadir` and `$boardsdir` on every front page load with a pre-rendered HTML cache (`activethreads.cache`).
* ** Configurable TTL:** Implemented a 300-second (5-minute) Time-To-Live backup safety net to guarantee self-healing cache refreshes.

### 4. Real-Time Cache Invalidation Hooks (`unlink`)

* ** Instant Synchronization:** Integrated targeted `unlink` cache-clearing hooks across core action scripts to instantly flush stale cache data the moment changes occur:
* **`Post.pm`:** Clears cache on new topic or reply submissions.
* **`ModifyMessage.pm`:** Clears cache on post and subject edits.
* **`RemoveTopic.pm`:** Clears cache on thread and post deletions.
* **`MoveSplitSplice.pm`:** Clears cache on thread splits, merges, and moves.

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