Sort tab configs alphabetically by name (#9258)

Closes #9132
Description
Tab configs loaded from ~/.warp/tab_configs/ appeared in
non-deterministic order in the + menu and the default session mode
dropdown in settings. The root cause is WalkDir returning directory
entries in filesystem order, which varies across platforms and runs.

Added a case-insensitive alphabetical sort by name in load_tab_configs()
(app/src/user_config/native.rs), so all consumers receive a stable,
predictable ordering without needing per-site sorting.
Testing
- cargo check -p warp passes with no errors.
- No new tests added. The change is a single sort_by call on an existing
Vec<TabConfig> — the sorting behavior is deterministic and trivially
correct. Manual verification: create multiple .toml files in
~/.warp/tab_configs/ with names like "Zebra", "alpha", "Beta" and
confirm they appear as alpha, Beta, Zebra in the + menu.
Agent Mode
- Warp Agent Mode - This PR was created via Warp's AI Agent Mode
Changelog Entries for Stable                 

CHANGELOG-BUG-FIX: Tab configs in the + menu and default session mode
dropdown are now sorted alphabetically by name instead of appearing in
random order.

app/src/user_config/mod.rs

@@ -17,6 +17,8 @@ use std::path::PathBuf;
 use warp_core::ui::theme::WarpTheme;
 use warpui::{Entity, ModelContext, SingletonEntity};
 
+#[cfg(test)]
+pub(crate) use imp::load_tab_configs;
 #[cfg(feature = "local_fs")]
 pub use imp::load_workflows;
 pub use imp::{load_launch_configs, load_theme_configs};

app/src/user_config/mod_test.rs

@@ -1,5 +1,6 @@
 use super::*;
 use std::collections::HashMap;
+use std::io::Write;
 use std::path::Path;
 
 use crate::launch_configs::launch_config::PaneTemplateType;
@@ -112,3 +113,64 @@ fn test_sanitize_toml_base_name_replaces_spaces_and_dots() {
 fn test_sanitize_toml_base_name_falls_back_for_empty_result() {
     assert_eq!(sanitize_toml_base_name("..."), "worktree");
 }
+
+fn write_tab_config_toml(dir: &Path, file_name: &str, config_name: &str) {
+    let path = dir.join(file_name);
+    let mut f = std::fs::File::create(path).unwrap();
+    write!(f, "name = \"{}\"", config_name).unwrap();
+}
+
+#[cfg(feature = "local_fs")]
+#[test]
+fn test_load_tab_configs_sorts_case_insensitive() {
+    let dir = tempfile::tempdir().unwrap();
+    write_tab_config_toml(dir.path(), "zebra.toml", "Zebra");
+    write_tab_config_toml(dir.path(), "alpha.toml", "alpha");
+    write_tab_config_toml(dir.path(), "beta.toml", "Beta");
+
+    let (configs, errors) = load_tab_configs(dir.path());
+
+    assert!(errors.is_empty());
+    let names: Vec<&str> = configs.iter().map(|c| c.name.as_str()).collect();
+    assert_eq!(names, vec!["alpha", "Beta", "Zebra"]);
+}
+
+#[cfg(feature = "local_fs")]
+#[test]
+fn test_load_tab_configs_deterministic_tie_breaking() {
+    let dir = tempfile::tempdir().unwrap();
+    write_tab_config_toml(dir.path(), "upper.toml", "Alpha");
+    write_tab_config_toml(dir.path(), "lower.toml", "alpha");
+
+    let (configs, errors) = load_tab_configs(dir.path());
+
+    assert!(errors.is_empty());
+    let names: Vec<&str> = configs.iter().map(|c| c.name.as_str()).collect();
+    assert_eq!(names, vec!["Alpha", "alpha"]);
+}
+
+#[cfg(feature = "local_fs")]
+#[test]
+fn test_load_tab_configs_empty_directory() {
+    let dir = tempfile::tempdir().unwrap();
+
+    let (configs, errors) = load_tab_configs(dir.path());
+
+    assert!(configs.is_empty());
+    assert!(errors.is_empty());
+}
+
+#[cfg(feature = "local_fs")]
+#[test]
+fn test_load_tab_configs_skips_non_toml_files() {
+    let dir = tempfile::tempdir().unwrap();
+    write_tab_config_toml(dir.path(), "real.toml", "Real");
+    std::fs::write(dir.path().join("readme.md"), "not a config").unwrap();
+    std::fs::write(dir.path().join("data.json"), "{}").unwrap();
+
+    let (configs, errors) = load_tab_configs(dir.path());
+
+    assert!(errors.is_empty());
+    assert_eq!(configs.len(), 1);
+    assert_eq!(configs[0].name, "Real");
+}

app/src/user_config/native.rs

@@ -204,6 +204,11 @@ pub fn load_tab_configs(tab_config_path: &Path) -> (Vec<TabConfig>, Vec<TabConfi
             Err(error) => errors.push(error),
         }
     }
+    configs.sort_by(|a, b| {
+        let a_name = a.name.to_lowercase();
+        let b_name = b.name.to_lowercase();
+        a_name.cmp(&b_name).then_with(|| a.name.cmp(&b.name))
+    });
     (configs, errors)
 }