chore: drop tool-name markers from source comments

Seventeen comments opened with a tag naming the tool that wrote them.
The tag goes and each comment keeps its reasoning, now starting as a
plain sentence. None of the reasoning changes.

The AGENTS.md note in .gitignore drops the story of how the file got
into the tree and keeps the one fact a reader needs: its advice to run
go fmt is destructive on this CRLF working tree.

Comments only; no code, build or test changes.

plugins/velocity/src/main/java/best/lolicon/felis/velocity/FelisVelocityPlugin.java

@@ -691,7 +691,7 @@ public final class FelisVelocityPlugin {
                                             StringArgumentType.getString(ctx, "server"));
                                     return Command.SINGLE_SUCCESS;
                                 })))
-                // ponytail: Brigadier matches literals before arguments, so a player
+                // Brigadier matches literals before arguments, so a player
                 // actually named "accept"/"deny" cannot be invited by name. They can
                 // still reach the server with /felis go, and renaming the subcommands
                 // would break the click handlers for a case worth less than that.
@@ -868,7 +868,7 @@ public final class FelisVelocityPlugin {
                     NamedTextColor.YELLOW));
             return;
         }
-        // ponytail: peek-then-take is not atomic — an invite landing in that window is
+        // Peek-then-take is not atomic — an invite landing in that window is
         // taken instead of the one just validated. "Newest wins" is already the rule the
         // book enforces, so the outcome is one this player would have got anyway; make it
         // a computeIfPresent if invites ever arrive fast enough for anyone to notice.
@@ -899,7 +899,7 @@ public final class FelisVelocityPlugin {
     // notifyInviter closes the loop for whoever sent the invite; without it they wait on a
     // prompt they can never see the answer to. Silently skipped if they left in the meantime.
     //
-    // ponytail: ACCEPTED means the transfer was handed to the waiting queue, which is as far
+    // ACCEPTED means the transfer was handed to the waiting queue, which is as far
     // as this can see synchronously — a wake that fails later is reported to the guest only.
     private void notifyInviter(InviteBook.Invite invite, String who, Answer answer) {
         proxy.getPlayer(invite.from()).ifPresent(p -> {

plugins/velocity/src/main/java/best/lolicon/felis/velocity/InviteBook.java

@@ -56,7 +56,7 @@ final class InviteBook {
      * cooldownRemaining is how long the sender must still wait, in millis, or 0 when they
      * may send now.
      *
-     * <p>ponytail: one global stamp per sender, so inviting Alex also holds off inviting
+     * <p>One global stamp per sender, so inviting Alex also holds off inviting
      * Steve. That is the shape that actually stops the spam — a per-(sender, invitee) key
      * would let one sender paper every player on the proxy at once, which is the thing
      * being rate-limited. Key it per pair only if a real group of players complains.