refactored and condensed technical documentation and comments across the codebase to improve readability

lib/push/chat_thread_store.dart

@@ -77,15 +77,11 @@ List<ThreadMessage> removeThreadNid(List<ThreadMessage> messages, int nid) =>
 
 /// History for the next notification after [message] arrives, given whether
 /// the chat's previous notification is still on screen ([isActive]):
+/// `true` → stacks onto existing history; `false` → notification gone
+/// (dismissed/read), thread restarts with only [message]; `null` → probe
+/// failed/unsupported, keep stacking (degraded stacking never loses a message).
 ///
-/// - `true` → the user hasn't dismissed/read it, so [message] STACKS onto the
-///   existing history.
-/// - `false` → the notification is gone (swiped away or the chat was read
-///   without our cleanup running), so the thread RESTARTS with only [message].
-/// - `null` → the active-notification probe failed or isn't supported; keep
-///   stacking defensively — degraded stacking never loses a message.
-///
-/// Android provides no reliable "notification dismissed" callback, so the
+/// Android has no reliable "notification dismissed" callback, so the
 /// visible-state probe at append time is the substitute.
 List<ThreadMessage> threadAfterIncoming(
   List<ThreadMessage> existing,
@@ -98,11 +94,9 @@ List<ThreadMessage> threadAfterIncoming(
 }
 
 /// MessagingStyle header per Android convention: a 1:1 chat gets NO
-/// `conversationTitle` — the system then shows the person once as the header
-/// and plain texts per line; setting a title would repeat the name on every
-/// row. Groups get the ROOM NAME as title (parsed from the subject) plus
-/// per-line sender names; when no room name is known, >1 distinct sender
-/// still marks the thread as group with the last sender as title fallback.
+/// `conversationTitle` (setting one would repeat the person's name on every
+/// row); groups use the room name as title, falling back to the last sender
+/// when there is >1 distinct sender but no room name is known.
 ({String? conversationTitle, bool groupConversation}) conversationHeader(
   List<ThreadMessage> messages,
 ) {