claude-code: add support for output styles

Adds an option to populate the output_styles directory,
which is used by Claude Code to make custom output styles available.

tests/modules/programs/claude-code/default.nix

@@ -17,4 +17,6 @@
   claude-code-commands-path = ./commands-path.nix;
   claude-code-skills-path = ./skills-path.nix;
   claude-code-mixed-content = ./mixed-content.nix;
+  claude-code-output-styles = ./output-styles.nix;
+  claude-code-output-styles-not-set = ./output-styles-not-set.nix;
 }

tests/modules/programs/claude-code/output-styles-not-set.nix

@@ -0,0 +1,12 @@
+{
+  programs.claude-code = {
+    enable = true;
+    settings = {
+      theme = "dark";
+    };
+  };
+
+  nmt.script = ''
+    assertPathNotExists home-files/.claude/output-styles
+  '';
+}

tests/modules/programs/claude-code/output-styles.nix

@@ -0,0 +1,25 @@
+{
+  programs.claude-code = {
+    enable = true;
+    outputStyles = {
+      inline-style = ''
+        # Inline Output Style
+
+        This is an inline output style for testing.
+        It should be written to .claude/output-styles/inline-style.md
+      '';
+      path-style = ./test-output-style.md;
+    };
+  };
+
+  nmt.script = ''
+    assertFileExists home-files/.claude/output-styles/inline-style.md
+    assertFileExists home-files/.claude/output-styles/path-style.md
+
+    assertFileContent home-files/.claude/output-styles/path-style.md \
+      ${./test-output-style.md}
+
+    assertFileRegex home-files/.claude/output-styles/inline-style.md \
+      'This is an inline output style for testing'
+  '';
+}

tests/modules/programs/claude-code/test-output-style.md

@@ -0,0 +1,4 @@
+# Test Output Style
+
+This is a test output style loaded from a file path.
+Used to verify path support functionality for output styles.