docs: map existing codebase

.planning/codebase/STACK.md

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+# Technology Stack
+
+**Analysis Date:** 2026-03-27
+
+## Languages
+
+**Primary:**
+- JavaScript (Node.js) - Core framework and tooling
+- CommonJS (`.cjs`) - Module format for all library files
+- Markdown - Configuration, documentation, and state files
+
+## Runtime
+
+**Environment:**
+- Node.js (version not explicitly specified, uses `#!/usr/bin/env node` shebang)
+
+**Package Manager:**
+- npm (inferred from package.json presence)
+- Lockfile: Not detected in codebase
+
+## Frameworks
+
+**Core:**
+- Get Shit Done (GSD) Framework v1.29.0 - Agentic code orchestration and planning
+- Native Node.js APIs - `child_process`, `fs`, `path`
+
+**Search & Web:**
+- Brave Search API - Web search integration via HTTP fetch
+
+**Build/Dev:**
+- Node.js built-in utilities - No external build tool detected
+
+## Key Dependencies
+
+**Critical:**
+- `child_process` - Subprocess execution for git commands and CLI operations
+- `fs` - File system operations for planning document management
+- `path` - Cross-platform path handling
+- `os` - Environment detection (home directory, temp directories)
+
+**Infrastructure:**
+- `fetch` API (native Node.js) - HTTP requests for Brave Search API
+
+## Configuration
+
+**Environment:**
+- Stored in `~/.gsd/` directory with separate API key files
+- Environment variable overrides: `BRAVE_API_KEY`, `FIRECRAWL_API_KEY`, `EXA_API_KEY`
+
+**Key Configuration Files:**
+- `.planning/config.json` - Project-wide configuration and feature flags
+- `settings.json` - Agent-specific settings (per `./.agent/`, `./.claude/`, `./.gemini/`, etc.)
+- `.gsd-file-manifest.json` - File integrity tracking with SHA256 hashes
+
+**Configuration Features:**
+- Multi-repository workspace support
+- Model profile resolution
+- Milestone and workstream management
+- Phase numbering strategies (decimal or custom)
+
+## Platform Requirements
+
+**Development:**
+- Node.js with built-in ES2020+ support
+- Git (for repository operations and commits)
+- Bash/Shell environment for command execution
+- File system with support for symlinks and deep directory structures
+
+**Production:**
+- Self-contained Node.js CLI tool
+- No external runtime required beyond Node.js
+- Execution via `node gsd-tools.cjs` or direct command invocation
+
+---
+
+*Stack analysis: 2026-03-27*