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/phase0/0.2.2-create-config-interface.md

@@ -0,0 +1,59 @@
+# Task 0.2.2: Create Config Interface
+
+## Metadata
+- **Task ID**: 0.2.2
+- **Title**: Create Config Interface
+- **Phase**: 0 - Project Setup & Foundation
+- **Section**: 0.2 Configuration System
+- **Status**: Pending
+- **Priority**: High
+- **Estimated Time**: 15 minutes
+- **Dependencies**: 0.2.1
+
+## Description
+Create the `ConfigProvider` interface in `pkg/config/` to abstract configuration access. This interface will be used by all modules and services.
+
+## Requirements
+- Define interface in `pkg/config/config.go`
+- Include methods for type-safe access
+- Support nested configuration keys
+- Support unmarshaling into structs
+
+## Implementation Steps
+1. Create `pkg/config/config.go`
+2. Define `ConfigProvider` interface:
+   ```go
+   type ConfigProvider interface {
+       Get(key string) any
+       Unmarshal(v any) error
+       GetString(key string) string
+       GetInt(key string) int
+       GetBool(key string) bool
+       GetStringSlice(key string) []string
+   }
+   ```
+3. Add package documentation
+4. Export interface for use by modules
+
+## Acceptance Criteria
+- [ ] `pkg/config/config.go` exists
+- [ ] `ConfigProvider` interface is defined
+- [ ] Interface methods match requirements
+- [ ] Package documentation is present
+- [ ] Interface compiles without errors
+
+## Related ADRs
+- [ADR-0004: Configuration Management](../../adr/0004-configuration-management.md)
+
+## Implementation Notes
+- Interface should be minimal and focused
+- Additional methods can be added later if needed
+- Consider adding `GetDuration()` for time.Duration values
+- Consider adding `IsSet(key string) bool` to check if key exists
+
+## Testing
+```bash
+go build ./pkg/config
+go vet ./pkg/config
+```
+