terminal/tmux: better formatting for notifications and actions

src/terminal/tmux/control.zig

@@ -531,7 +531,31 @@ pub const Notification = union(enum) {
         session_id: usize,
         name: []const u8,
     },
-};
+
+    pub fn format(self: Notification, writer: *std.Io.Writer) !void {
+        const T = Notification;
+        const info = @typeInfo(T).@"union";
+
+        try writer.writeAll(@typeName(T));
+        if (info.tag_type) |TagType| {
+            try writer.writeAll("{ .");
+            try writer.writeAll(@tagName(@as(TagType, self)));
+            try writer.writeAll(" = ");
+
+            inline for (info.fields) |u_field| {
+                if (self == @field(TagType, u_field.name)) {
+                    const value = @field(self, u_field.name);
+                    switch (u_field.type) {
+                        []const u8 => try writer.print("\"{s}\"", .{std.mem.trim(u8, value, " \t\r\n")}),
+                        else => try writer.print("{any}", .{value}),
+                    }
+                }
+            }
+
+            try writer.writeAll(" }");
+        }
+    }
+            };
 
 test "tmux begin/end empty" {
     const testing = std.testing;

src/terminal/tmux/viewer.zig

@@ -64,6 +64,30 @@ pub const Viewer = struct {
         /// are guaranteed to be stable. Additionally, tmux (as of Dec 2025)
         /// never re-uses window IDs within a server process lifetime.
         windows: []const Window,
+
+        pub fn format(self: Action, writer: *std.Io.Writer) !void {
+            const T = Action;
+            const info = @typeInfo(T).@"union";
+
+            try writer.writeAll(@typeName(T));
+            if (info.tag_type) |TagType| {
+                try writer.writeAll("{ .");
+                try writer.writeAll(@tagName(@as(TagType, self)));
+                try writer.writeAll(" = ");
+
+                inline for (info.fields) |u_field| {
+                    if (self == @field(TagType, u_field.name)) {
+                        const value = @field(self, u_field.name);
+                        switch (u_field.type) {
+                            []const u8 => try writer.print("\"{s}\"", .{std.mem.trim(u8, value, " \t\r\n")}),
+                            else => try writer.print("{any}", .{value}),
+                        }
+                    }
+                }
+
+                try writer.writeAll(" }");
+            }
+        }
     };
 
     pub const Input = union(enum) {

src/termio/stream_handler.zig

@@ -384,7 +384,7 @@ pub const StreamHandler = struct {
                 // If tmux control mode is disabled at the build level,
                 // then this whole block shouldn't be analyzed.
                 if (comptime !tmux_enabled) break :tmux;
-                log.info("tmux control mode event cmd={}", .{tmux});
+                log.info("tmux control mode event cmd={f}", .{tmux});
 
                 switch (tmux) {
                     .enter => {
@@ -415,7 +415,7 @@ pub const StreamHandler = struct {
                     // This can only really happen if we failed to
                     // initialize the viewer on enter.
                     log.info(
-                        "received tmux control mode command without viewer: {}",
+                        "received tmux control mode command without viewer: {f}",
                         .{tmux},
                     );
 
@@ -423,7 +423,7 @@ pub const StreamHandler = struct {
                 };
 
                 for (try viewer.next(.{ .tmux = tmux })) |action| {
-                    log.info("tmux viewer action={}", .{action});
+                    log.info("tmux viewer action={f}", .{action});
                     switch (action) {
                         .exit => {
                             // We ignore this because we will fully exit when