feat: add configurable tab bar status (#2586)

* feat: show a zoom indicator in the desktop tab bar

Reserve the right edge of the tab row for a ZOOM pill while the
focused pane is zoomed, matching the accent style of the mode bars.
The per-tab Z suffix stays; the pill makes the zoomed state visible
at a glance like tmux's status-right flag.

* feat: optionally show the hostname in the desktop tab bar

Add ui.tab_bar_hostname to display the machine's hostname at the right
edge of the tab row, like tmux's #h in status-right. The value resolves
where the server renders, so remote sessions show the remote host. Off
by default.

* fix: strip control characters from the tab bar hostname

* fix: hide the hostname when it would squeeze out the tab strip

* feat: add configurable tab bar status

* fix: harden tab bar status updates

* fix: terminate tab bar status process trees

* fix: disable status commands on unsupported platforms

* fix: skip unchanged status command renders

* fix: keep tab bar status opt-in by default

---------

Co-authored-by: David Heinemeier Hansson <david@hey.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/src/config.rs b/src/config.rs
index 858ca632..88645061 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -5,6 +5,7 @@ mod keybinds;
 mod model;
 mod sidebar;
 mod sound;
+mod tab_bar;
 mod theme;
 
 pub use self::{
@@ -30,11 +31,20 @@ pub use self::{
         SpaceSidebarToken, SpacesSidebarConfig,
     },
     sound::SoundConfig,
+    tab_bar::TabBarRightEntryConfig,
     theme::{parse_color, CustomThemeColors, ThemeConfig, THEME_NAMES},
 };
 
 pub(crate) use self::keybinds::parse_key_combo;
-pub(crate) use self::{io::upsert_top_level_bool, theme::canonical_theme_name};
+pub(crate) use self::{
+    io::upsert_top_level_bool,
+    tab_bar::{
+        parse_tab_bar_datetime_format, tab_bar_right_diagnostics,
+        MAX_TAB_BAR_COMMAND_INTERVAL_SECONDS, MAX_TAB_BAR_COMMAND_TIMEOUT_SECONDS,
+        MAX_TAB_BAR_RIGHT_ENTRIES,
+    },
+    theme::canonical_theme_name,
+};
 
 pub const CONFIG_PATH_ENV_VAR: &str = "HERDR_CONFIG_PATH";
 pub const DEFAULT_SCROLLBACK_LIMIT_BYTES: usize = 10_000_000;
@@ -74,6 +84,7 @@ impl Config {
             .chain(self.remote_image_paste_key().err())
             .chain(self.theme.diagnostics())
             .chain(self.ui.sound.diagnostics())
+            .chain(tab_bar_right_diagnostics(&self.ui.tab_bar_right))
             .chain(self.invalid_sidebar_bounds_diagnostic())
             .collect()
     }