Give the message log to Messages as its own fields

Not a pure move: state moves. Pardes's three message-log fields
(`messages: [message_log]LoggedMessage`, `messages_head`, `messages_len`)
become the fields of Messages.zig itself (`log`, `head`, `len`), and
Pardes embeds one as `messages: Messages = .{}`. messageLog reads only the
ring, so it now takes `m: *const Messages` and is called
`p.messages.messageLog(i)` (Output's +Messages view and the log test);
logMessage still needs the panes and the 9P event log, so it keeps
`p: *Pardes` and writes `p.messages.log/head/len`. No behaviour change.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 2 insertions, 6 deletions

diff --git a/src/pardes.zig b/src/pardes.zig
index 44f0d2ea..d2ac5868 100644
--- a/src/pardes.zig
+++ b/src/pardes.zig
@@ -3777,12 +3777,8 @@ pub const Pardes = struct {
     /// The in-program answers behind every unimplemented host method. Per
     /// instance, so several cores behind one fan-out host stay independent.
     fallback: host_io.Fallback,
-    /// The message-row log: a fixed ring, never allocated, never grown. See
-    /// `logMessage` and the `Messages` builtin.
-    messages: [limits.message_log]Messages.LoggedMessage = @splat(.{}),
-    /// Next slot to write. `messages_len` saturates at the ring's size.
-    messages_head: usize = 0,
-    messages_len: usize = 0,
+    /// The message-row log (see Messages.zig).
+    messages: Messages = .{},
     in_q: [64]Event = undefined,
     in_head: usize = 0,
     in_len: usize = 0,