docs: add implementation plan, ADRs, and task tracking system

- Add comprehensive 8-phase implementation plan (docs/plan.md)
- Add 28 Architecture Decision Records (docs/adr/) covering all phases
- Add task tracking system with 283+ task files (docs/stories/)
- Add task generator script for automated task file creation
- Add reference playbooks and requirements documentation

This commit establishes the complete planning foundation for the Go
Platform implementation, documenting all architectural decisions and
providing detailed task breakdown for Phases 0-8.

docs/stories/phase0/0.2.1-install-githubcomspf13viper-and-githubcomspf13cobr.md

@@ -0,0 +1,47 @@
+# Task 0.2.1: Install Configuration Dependencies
+
+## Metadata
+- **Task ID**: 0.2.1
+- **Title**: Install Configuration Dependencies
+- **Phase**: 0 - Project Setup & Foundation
+- **Section**: 0.2 Configuration System
+- **Status**: Pending
+- **Priority**: High
+- **Estimated Time**: 5 minutes
+- **Dependencies**: 0.1.1
+
+## Description
+Install Viper and Cobra packages for configuration management and CLI support.
+
+## Requirements
+- Install `github.com/spf13/viper` v1.18.0+
+- Install `github.com/spf13/cobra` v1.8.0+
+- Add to `go.mod` with proper version constraints
+
+## Implementation Steps
+1. Run `go get github.com/spf13/viper@v1.18.0`
+2. Run `go get github.com/spf13/cobra@v1.8.0`
+3. Run `go mod tidy` to update dependencies
+4. Verify packages in `go.mod`
+
+## Acceptance Criteria
+- [ ] Viper is listed in `go.mod`
+- [ ] Cobra is listed in `go.mod`
+- [ ] `go mod verify` passes
+- [ ] Dependencies are properly versioned
+
+## Related ADRs
+- [ADR-0004: Configuration Management](../../adr/0004-configuration-management.md)
+
+## Implementation Notes
+- Use specific versions for reproducibility
+- Consider using `go get -u` for latest patch versions
+- Document version choices in ADR
+
+## Testing
+```bash
+go mod verify
+go list -m github.com/spf13/viper
+go list -m github.com/spf13/cobra
+```
+