Fix shell-integration-features being ignored with manual shell integration (#5048)

## Descriptions

The code was short-circuiting the shell integration setup when
`shell-integration = none`, which prevented the feature environment
variables from being set. These environment variables are needed even
for manual shell integration to work properly.

## Changes

- Extracted feature environment variables setup into a separate
`setup_features` function

- Modified the shell integration initialization to ensure features are
set up even when `shell-integration = none`

<img width="1126" alt="image"
src="https://github.com/user-attachments/assets/ceeb33f5-26ee-4a3b-a6d5-eed57848c96c"
/>


Fixes https://github.com/ghostty-org/ghostty/issues/5046

src/config/Config.zig

@@ -1670,7 +1670,9 @@ keybind: Keybinds = .{},
 /// The default value is `detect`.
 @"shell-integration": ShellIntegration = .detect,
 
-/// Shell integration features to enable if shell integration itself is enabled.
+/// Shell integration features to enable. These require our shell integration
+/// to be loaded, either automatically via shell-integration or manually.
+///
 /// The format of this is a list of features to enable separated by commas. If
 /// you prefix a feature with `no-` then it is disabled. If you omit a feature,
 /// its default value is used, so you must explicitly disable features you don't

src/termio/Exec.zig

@@ -875,7 +875,11 @@ const Subprocess = struct {
             };
 
             const force: ?shell_integration.Shell = switch (cfg.shell_integration) {
-                .none => break :shell .{ null, default_shell_command },
+                .none => {
+                    // Even if shell integration is none, we still want to set up the feature env vars
+                    try shell_integration.setupFeatures(&env, cfg.shell_integration_features);
+                    break :shell .{ null, default_shell_command };
+                },
                 .detect => null,
                 .bash => .bash,
                 .elvish => .elvish,

src/termio/shell_integration.zig

@@ -58,7 +58,21 @@ pub fn setup(
         break :exe std.fs.path.basename(command[0..idx]);
     };
 
-    const result: ShellIntegration = shell: {
+    const result = try setupShell(alloc_arena, resource_dir, command, env, exe);
+
+    // Setup our feature env vars
+    try setupFeatures(env, features);
+
+    return result;
+}
+
+fn setupShell(
+    alloc_arena: Allocator,
+    resource_dir: []const u8,
+    command: []const u8,
+    env: *EnvMap,
+    exe: []const u8,
+) !?ShellIntegration {
     if (std.mem.eql(u8, "bash", exe)) {
         // Apple distributes their own patched version of Bash 3.2
         // on macOS that disables the ENV-based POSIX startup path.
@@ -80,7 +94,7 @@ pub fn setup(
             resource_dir,
             env,
         ) orelse return null;
-            break :shell .{
+        return .{
             .shell = .bash,
             .command = new_command,
         };
@@ -88,7 +102,7 @@ pub fn setup(
 
     if (std.mem.eql(u8, "elvish", exe)) {
         try setupXdgDataDirs(alloc_arena, resource_dir, env);
-            break :shell .{
+        return .{
             .shell = .elvish,
             .command = try alloc_arena.dupe(u8, command),
         };
@@ -96,7 +110,7 @@ pub fn setup(
 
     if (std.mem.eql(u8, "fish", exe)) {
         try setupXdgDataDirs(alloc_arena, resource_dir, env);
-            break :shell .{
+        return .{
             .shell = .fish,
             .command = try alloc_arena.dupe(u8, command),
         };
@@ -104,21 +118,13 @@ pub fn setup(
 
     if (std.mem.eql(u8, "zsh", exe)) {
         try setupZsh(resource_dir, env);
-            break :shell .{
+        return .{
             .shell = .zsh,
             .command = try alloc_arena.dupe(u8, command),
         };
     }
 
     return null;
-    };
-
-    // Setup our feature env vars
-    if (!features.cursor) try env.put("GHOSTTY_SHELL_INTEGRATION_NO_CURSOR", "1");
-    if (!features.sudo) try env.put("GHOSTTY_SHELL_INTEGRATION_NO_SUDO", "1");
-    if (!features.title) try env.put("GHOSTTY_SHELL_INTEGRATION_NO_TITLE", "1");
-
-    return result;
 }
 
 test "force shell" {
@@ -138,6 +144,58 @@ test "force shell" {
     }
 }
 
+/// Setup shell integration feature environment variables without
+/// performing full shell integration setup.
+pub fn setupFeatures(
+    env: *EnvMap,
+    features: config.ShellIntegrationFeatures,
+) !void {
+    if (!features.cursor) try env.put("GHOSTTY_SHELL_INTEGRATION_NO_CURSOR", "1");
+    if (!features.sudo) try env.put("GHOSTTY_SHELL_INTEGRATION_NO_SUDO", "1");
+    if (!features.title) try env.put("GHOSTTY_SHELL_INTEGRATION_NO_TITLE", "1");
+}
+
+test "setup features" {
+    const testing = std.testing;
+
+    var arena = ArenaAllocator.init(testing.allocator);
+    defer arena.deinit();
+    const alloc = arena.allocator();
+
+    // Test: all features enabled (no environment variables should be set)
+    {
+        var env = EnvMap.init(alloc);
+        defer env.deinit();
+
+        try setupFeatures(&env, .{ .cursor = true, .sudo = true, .title = true });
+        try testing.expect(env.get("GHOSTTY_SHELL_INTEGRATION_NO_CURSOR") == null);
+        try testing.expect(env.get("GHOSTTY_SHELL_INTEGRATION_NO_SUDO") == null);
+        try testing.expect(env.get("GHOSTTY_SHELL_INTEGRATION_NO_TITLE") == null);
+    }
+
+    // Test: all features disabled
+    {
+        var env = EnvMap.init(alloc);
+        defer env.deinit();
+
+        try setupFeatures(&env, .{ .cursor = false, .sudo = false, .title = false });
+        try testing.expectEqualStrings("1", env.get("GHOSTTY_SHELL_INTEGRATION_NO_CURSOR").?);
+        try testing.expectEqualStrings("1", env.get("GHOSTTY_SHELL_INTEGRATION_NO_SUDO").?);
+        try testing.expectEqualStrings("1", env.get("GHOSTTY_SHELL_INTEGRATION_NO_TITLE").?);
+    }
+
+    // Test: mixed features
+    {
+        var env = EnvMap.init(alloc);
+        defer env.deinit();
+
+        try setupFeatures(&env, .{ .cursor = false, .sudo = true, .title = false });
+        try testing.expectEqualStrings("1", env.get("GHOSTTY_SHELL_INTEGRATION_NO_CURSOR").?);
+        try testing.expect(env.get("GHOSTTY_SHELL_INTEGRATION_NO_SUDO") == null);
+        try testing.expectEqualStrings("1", env.get("GHOSTTY_SHELL_INTEGRATION_NO_TITLE").?);
+    }
+}
+
 /// Setup the bash automatic shell integration. This works by
 /// starting bash in POSIX mode and using the ENV environment
 /// variable to load our bash integration script. This prevents