v1.4.0: Major Skills Expansion - 75 Total Skills

skills/superpowers/tests/subagent-driven-dev/go-fractals/design.md

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+# Go Fractals CLI - Design
+
+## Overview
+
+A command-line tool that generates ASCII art fractals. Supports two fractal types with configurable output.
+
+## Usage
+
+```bash
+# Sierpinski triangle
+fractals sierpinski --size 32 --depth 5
+
+# Mandelbrot set
+fractals mandelbrot --width 80 --height 24 --iterations 100
+
+# Custom character
+fractals sierpinski --size 16 --char '#'
+
+# Help
+fractals --help
+fractals sierpinski --help
+```
+
+## Commands
+
+### `sierpinski`
+
+Generates a Sierpinski triangle using recursive subdivision.
+
+Flags:
+- `--size` (default: 32) - Width of the triangle base in characters
+- `--depth` (default: 5) - Recursion depth
+- `--char` (default: '*') - Character to use for filled points
+
+Output: Triangle printed to stdout, one line per row.
+
+### `mandelbrot`
+
+Renders the Mandelbrot set as ASCII art. Maps iteration count to characters.
+
+Flags:
+- `--width` (default: 80) - Output width in characters
+- `--height` (default: 24) - Output height in characters
+- `--iterations` (default: 100) - Maximum iterations for escape calculation
+- `--char` (default: gradient) - Single character, or omit for gradient " .:-=+*#%@"
+
+Output: Rectangle printed to stdout.
+
+## Architecture
+
+```
+cmd/
+  fractals/
+    main.go           # Entry point, CLI setup
+internal/
+  sierpinski/
+    sierpinski.go     # Algorithm
+    sierpinski_test.go
+  mandelbrot/
+    mandelbrot.go     # Algorithm
+    mandelbrot_test.go
+  cli/
+    root.go           # Root command, help
+    sierpinski.go     # Sierpinski subcommand
+    mandelbrot.go     # Mandelbrot subcommand
+```
+
+## Dependencies
+
+- Go 1.21+
+- `github.com/spf13/cobra` for CLI
+
+## Acceptance Criteria
+
+1. `fractals --help` shows usage
+2. `fractals sierpinski` outputs a recognizable triangle
+3. `fractals mandelbrot` outputs a recognizable Mandelbrot set
+4. `--size`, `--width`, `--height`, `--depth`, `--iterations` flags work
+5. `--char` customizes output character
+6. Invalid inputs produce clear error messages
+7. All tests pass