fix(buffer): use dynamic buffer size to prevent unnecessary buffer cleanups

Refactor buffer trimming logic to use dynamic line counts (_lines per entry)
against PAD_SIZE (10k) instead of fixed entry count (MAX_BUFFER_SIZE=200). This
prevents premature cleanups for short messages, reduces scrolling disruptions
during history loads, and scales better with rendered content size.

Delete oldest/newest entry from opposite end only when total lines approach
ncurses pad limit, minimizing unnecessary deletions.
Simplify overflow warning log by removing unused MAX_BUFFER_SIZE reference.

Update buffer.c header for improved DX:
- Add detailed module overview explaining role (in-memory UI buffer vs. DB
persistence), key features (trimming, metadata), and integration (ncurses).
- Shorten copyright/license boilerplate to concise pointer (LICENSE ref).
- Add fork notice; preserve original copyrights per GPLv3.

Partially addresses #36 (stuck scroll mitigation via fewer cleanups)
Related to #36

src/ui/buffer.c

@@ -1,37 +1,32 @@
 /*
  * buffer.c
- * vim: expandtab:ts=4:sts=4:sw=4
+ *
+ * Message buffer implementation for CProof.
+ *
+ * This module provides an in-memory buffer for managing active chat entries in the
+ * console-based XMPP client. Separate from persistent SQLite storage, it holds
+ * messages and metadata solely for UI rendering, ensuring responsive scrolling and
+ * display without exceeding ncurses pad limits (10k lines). By tracking rendered
+ * line counts per entry, it proactively trims content to prevent overflow, enabling
+ * seamless integration with ncurses for position-aware rendering.
+ *
+ * Key features and operations:
+ *   - Append/prepend entries (messages) with automatic line-based cleanup.
+ *   - Track cumulative lines for overflow prevention and efficient buffer sizing.
+ *   - Remove entries by ID or index; mark delivery receipts as received.
+ *   - Retrieve entries by index or ID for rendering and history queries.
+ *   - Store metadata including timestamps, senders, themes, and ncurses y-positions.
+ *
+ * CProof. Fork of Profanity (since 2025).
  *
  * Copyright (C) 2012 - 2019 James Booth <boothj5@gmail.com>
  * Copyright (C) 2019 - 2025 Michael Vetter <jubalh@iodoru.org>
+ * Copyright (C) 2025 CProof Developers
  *
- * This file is part of Profanity.
- *
- * Profanity is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * Profanity is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with Profanity.  If not, see <https://www.gnu.org/licenses/>.
- *
- * In addition, as a special exception, the copyright holders give permission to
- * link the code of portions of this program with the OpenSSL library under
- * certain conditions as described in each individual source file, and
- * distribute linked combinations including the two.
- *
- * You must obey the GNU General Public License in all respects for all of the
- * code used other than OpenSSL. If you modify file(s) with this exception, you
- * may extend this exception to your version of the file(s), but you are not
- * obligated to do so. If you do not wish to do so, delete this exception
- * statement from your version. If you delete this exception statement from all
- * source files in the program, then also delete it here.
+ * Licensed under the GNU General Public License, version 3,
+ * with the OpenSSL exception. See LICENSE for details.
  *
+ * vim: expandtab:ts=4:sts=4:sw=4
  */
 
 #include "config.h"
@@ -54,7 +49,6 @@
 #include "ui/window.h"
 #include "ui/buffer.h"
 
-#define MAX_BUFFER_SIZE     200
 #define STRDUP_OR_NULL(str) ((str) ? strdup(str) : NULL)
 
 struct prof_buff_t
@@ -108,7 +102,7 @@ _buffer_add(ProfBuff buffer, const char* show_char, int pad_indent, GDateTime* t
 
     buffer->lines += e->_lines;
 
-    while (g_slist_length(buffer->entries) >= MAX_BUFFER_SIZE) {
+    while (buffer->lines >= PAD_SIZE) {
         // Delete message from the opposite size to free buffer
         GSList* buffer_entry_to_delete = append ? buffer->entries : g_slist_last(buffer->entries);
         ProfBuffEntry* entry_to_delete = (ProfBuffEntry*)buffer_entry_to_delete->data;
@@ -118,8 +112,8 @@ _buffer_add(ProfBuff buffer, const char* show_char, int pad_indent, GDateTime* t
     }
 
     if (from_jid && y_end_pos == y_start_pos) {
-        log_warning("Ncurses Overflow! From: %s, position: %d, ID: %s, append: %s, used message buffer size: %d, message buffer size: %d, rendered lines buffer size: %d",
-                    from_jid, y_start_pos, id, append ? "TRUE" : "FALSE", g_slist_length(buffer->entries), MAX_BUFFER_SIZE, PAD_SIZE);
+        log_warning("Ncurses Overflow! From: %s, position: %d, ID: %s, append: %s, used message buffer size: %d, rendered lines buffer size: %d",
+                    from_jid, y_start_pos, id, append ? "TRUE" : "FALSE", g_slist_length(buffer->entries), PAD_SIZE);
         // At this point we have a message that caused overflow of the render buffer.
         // Ideally, we want to clean other messages to rerender everything properly. To do so,
         // first we need to determine the size of the message that we are trying to display,