refactor: restructure MIA repository into modular architecture

[sparesparrow]

Summary

Comprehensive restructuring of the MIA repository from 40+ scattered directories into a clean, scalable domain-based architecture with clear separation of concerns.

Problem Solved

The repository had grown organically with:

• Multiple root-level directories (modules/, core/, rpi/, apps/, etc.)
• Unclear separation between platforms (Android, ESP32, RPi)
• Orchestration and infrastructure concerns mixed throughout
• Test files scattered without clear organization
• Development tools in various locations

Solution Delivered

Five organizational layers replacing the flat structure:

apps/                    → Platform-specific applications
├── android/             → Android companion app (Kotlin/Compose)
├── esp32/               → ESP32 firmware (PlatformIO)
└── rpi-backend/         → Raspberry Pi backend (Python + C++)
    ├── py-api/          → FastAPI REST/WebSocket gateway
    ├── cpp-audio/       → C++ audio/DSP implementations
    └── shared/          → Shared messaging and utilities

orchestration/           → AI and MCP services
├── mcp/modules/         → 15+ MCP microservices
│   └── shared/          → Canonical MCP framework
├── mcp/prompts/         → Voice command prompt templates
└── mia-agents/          → Agent configurations

infra/                   → Infrastructure and deployment
├── docker/              → Docker Compose configurations
├── deploy/              → Deployment scripts (RPi, AWS, K8s)
├── systemd/             → 11 systemd service definitions
└── conan/               → Conan profiles and recipes

tests/                   → Organized test suite
├── unit/                → Fast isolated component tests
├── integration/         → Integration and E2E tests
└── fixtures/            → Shared test fixtures and data

tools/                   → Developer utilities
├── ci/                  → CI/CD utilities and legacy workflows
└── local-dev/           → Local development scripts

Phases Completed

✅ Phase 1: Foundation

• Created target directory skeleton
• Documented architecture in ARCHITECTURE.md
• Set up .worktrees/ for isolated development

✅ Phase 2: Applications

• Consolidated Android app to apps/android/
• Consolidated ESP32 firmware to apps/esp32/
• Consolidated RPi backend to apps/rpi-backend/ with logical split (py-api, cpp-audio, shared)

✅ Phase 3: Orchestration

• Moved 15+ MCP modules to orchestration/mcp/modules/
• Moved voice command prompts to orchestration/mcp/prompts/
• Moved agent configurations to orchestration/mia-agents/
• Identified canonical MCP framework at orchestration/mcp/modules/shared/mcp_framework.py

✅ Phase 4: Infrastructure

• Moved Docker Compose to infra/docker/
• Moved deployment scripts to infra/deploy/
• Moved 11 systemd service files to infra/systemd/
• Moved Conan profiles to infra/conan/

✅ Phase 5: Tests & Tools

• Organized 6 unit test files to tests/unit/rpi-backend/
• Organized 5+ integration test files to tests/integration/scenarios/
• Created tests/integration/fixtures/ for shared test data
• Moved development scripts to tools/local-dev/
• Archived legacy CI workflows to tools/ci/legacy/

✅ Phase 6: Validation

• Verified all Python imports resolve correctly
• Updated CI workflow paths (.github/workflows/ci.yml)
• Updated pre-commit configuration
• Updated documentation (CLAUDE.md)
• Created comprehensive validation report

Statistics

Metric	Value
Files reorganized	547+
Directories created	15+
CI paths updated	6+
Documentation files created	5+
Commits created	11
Git history preserved	100% (git mv used throughout)

Files Changed

Documentation Created

• ARCHITECTURE.md - System architecture and layer descriptions
• tests/README.md - Test structure, naming conventions, and pytest markers
• tools/README.md - Development tools reference and common tasks
• docs/RESTRUCTURING_STATUS.md - Phase completion tracking and follow-up work
• docs/RESTRUCTURING_VALIDATION.md - Comprehensive validation report with success criteria

Files Updated

• .github/workflows/ci.yml - All paths updated to reference new directory structure
• .pre-commit-config.yaml - Linter paths updated
• CLAUDE.md - All path references updated
• .gitignore - Added .worktrees/ to prevent tracking

Validation Results ✅

Directory Structure ✅

• All platform code consolidated to apps/
• All orchestration code consolidated to orchestration/
• All infrastructure consolidated to infra/
• All tests organized to tests/
• All tools organized to tools/

Python Imports ✅

• orchestration.mcp.modules imports verified working
• apps/rpi-backend/py-api directory structure accessible
• Old modules/ directory successfully removed
• Test imports updated to new locations

CI/CD Workflows ✅

• Android build references apps/android/
• ESP32 build references apps/esp32/platformio.ini
• Python tests run from tests/
• Conan references infra/conan/conanfile.py
• All linters configured with correct exclude paths

Build Configurations ✅

• Conanfile moved to infra/conan/conanfile.py
• CI caches point to correct paths
• Pre-commit configuration updated
• Docker Compose files in infra/docker/
• Deployment scripts in infra/deploy/

Deployment Readiness ✅

The restructured repository is ready for:

• ✅ CI/CD pipeline execution
• ✅ Local development builds
• ✅ Docker-based deployments
• ✅ Python package installation
• ✅ Test execution

Backward Compatibility ✅

• ✅ No runtime code changed (only moved)
• ✅ No functionality altered
• ✅ No new dependencies added
• ✅ All imports updated or preserved
• ✅ No breaking changes to core systems

Follow-Up Work (Future PRs)

Immediate (Post-Merge)

1. Monitor first few CI builds with new structure
2. Update team documentation with new structure
3. Verify deployment pipeline with new paths

Short Term (Next Sprint)

1. Remove legacy directories:
   • mia-universal/ (duplicate structure)
   • android-device-workspace/ (local workspace)
   • containers/ (Docker files moved)
   • scripts/ (moved to tools/)
2. Consolidate schemas and protos to shared location
3. Update root README.md with structure navigation

Medium Term

1. Organize web components (future apps/web/)
2. Enhance CI to leverage path-based triggering
3. Create developer quickstart guide

Notes for Reviewers

• All changes use git mv to preserve commit history
• Feature branch created from main at commit 4e2ddcd
• 11 logical commits organized by phase
• No force-push conflicts
• All documentation created during restructuring included
• Validation report confirms all success criteria met

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Ready for merge ✅ All validation checks passed, all tests import successfully, all CI paths updated, documentation complete.