asciinema: Add module to configure package

Enabling and defining minimal config file example;

```nix
{
  programs.asciinema = {
    enable = true;
    settings = {
      session.idle_time_limit = 2;
    };
  };
}
```

...  _Should_ result in output `~/.config/asciinema/config.toml` of;

```toml
[session]
idle_time_limit = 2
```

Co-authored-by: Austin Horstman <khaneliman12@gmail.com>

modules/misc/news/2025/10/2025-10-02_19-36-31.nix

@@ -0,0 +1,14 @@
+{
+  time = "2025-10-03T02:36:31+00:00";
+  condition = true;
+  message = ''
+    A new module is available: `programs.asciinema`
+
+    `asciinema` is a tool for recording, replaying, publishing, and live
+    streaming terminal session.
+
+    This module enables declaring configuration via `.settings`, check the
+    official documentation for details;
+    https://docs.asciinema.org/manual/cli/quick-start/
+  '';
+}

modules/programs/asciinema.nix

@@ -0,0 +1,82 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+let
+  inherit (lib)
+    mkEnableOption
+    mkIf
+    mkOption
+    mkPackageOption
+    ;
+
+  formatter = pkgs.formats.toml { };
+
+  cfg = config.programs.asciinema;
+in
+{
+  meta.maintainers = [
+    lib.maintainers.S0AndS0
+  ];
+
+  options.programs.asciinema = {
+    enable = mkEnableOption "Enable installing asciinema and writing configuration file";
+
+    package = mkPackageOption pkgs "asciinema" {
+      nullable = true;
+    };
+
+    settings = mkOption {
+      inherit (formatter) type;
+
+      default = { };
+
+      example = {
+        server.url = "https://asciinema.example.com";
+
+        session = {
+          command = "/run/current-system/sw/bin/bash -l";
+          capture_input = true;
+          capture_env = "SHELL,TERM,USER";
+          idle_time_limit = 2;
+          pause_key = "^p";
+          add_marker_key = "^x";
+          prefix_key = "^a";
+        };
+
+        playback = {
+          speed = 2;
+          pause_key = "^p";
+          step_key = "s";
+          next_marker_key = "m";
+        };
+
+        notifications = {
+          enable = false;
+          command = ''tmux display-message "$TEXT"'';
+        };
+      };
+
+      description = ''
+        Declare-able configurations for asciinema written to
+        {file}`$XDG_CONFIG_HOME/asciinema/config.toml`.
+
+
+        Check official docs for available configurations;
+        https://docs.asciinema.org/manual/cli/configuration/v3/#config-file
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    xdg.configFile."asciinema/config.toml" = mkIf (cfg.settings != { }) {
+      source = formatter.generate "asciinema_config.toml" cfg.settings;
+    };
+
+    home.packages = mkIf (cfg.package != null) [
+      cfg.package
+    ];
+  };
+}

tests/modules/programs/asciinema/default.nix

@@ -0,0 +1,3 @@
+{
+  asciinema-settings = ./settings.nix;
+}

tests/modules/programs/asciinema/settings.nix

@@ -0,0 +1,60 @@
+{
+  programs.asciinema = {
+    enable = true;
+
+    settings = {
+      server.url = "https://asciinema.example.com";
+
+      session = {
+        command = "/run/current-system/sw/bin/bash -l";
+        capture_input = true;
+        capture_env = "SHELL,TERM,USER";
+        idle_time_limit = 2;
+        pause_key = "^p";
+        add_marker_key = "^x";
+        prefix_key = "^a";
+      };
+
+      playback = {
+        speed = 2;
+        pause_key = "^p";
+        step_key = "s";
+        next_marker_key = "m";
+      };
+
+      notifications = {
+        enable = false;
+        command = ''tmux display-message "$TEXT"'';
+      };
+    };
+  };
+
+  ## TODO: check that `command` quote escaping doesn't break things
+  nmt.script = ''
+    assertFileExists home-files/.config/asciinema/config.toml
+    assertFileContent home-files/.config/asciinema/config.toml \
+    ${builtins.toFile "expected.asciinema_config.toml" ''
+      [notifications]
+      command = "tmux display-message \"$TEXT\""
+      enable = false
+
+      [playback]
+      next_marker_key = "m"
+      pause_key = "^p"
+      speed = 2
+      step_key = "s"
+
+      [server]
+      url = "https://asciinema.example.com"
+
+      [session]
+      add_marker_key = "^x"
+      capture_env = "SHELL,TERM,USER"
+      capture_input = true
+      command = "/run/current-system/sw/bin/bash -l"
+      idle_time_limit = 2
+      pause_key = "^p"
+      prefix_key = "^a"
+    ''}
+  '';
+}