docs: add ADR-0011 (KubeRay), ADR-0012 (uv), update architecture docs

CODING-CONVENTIONS.md

@@ -36,13 +36,19 @@ handler-base/                # Shared library for all handlers
 │   ├── health.py            # K8s probes
 │   ├── telemetry.py         # OpenTelemetry
 │   └── clients/             # Service clients
+├── tests/
 └── pyproject.toml
 
 chat-handler/                # Text chat service
 voice-assistant/             # Voice pipeline service
-├── {name}.py                # Standalone version
-├── {name}_v2.py             # Handler-base version (preferred)
-└── Dockerfile.v2
+pipeline-bridge/             # Workflow engine bridge
+├── {name}.py                # Handler implementation (uses handler-base)
+├── pyproject.toml           # PEP 621 project metadata (see ADR-0012)
+├── uv.lock                  # Deterministic lock file
+├── tests/
+│   ├── conftest.py
+│   └── test_{name}.py
+└── Dockerfile
 
 argo/                        # Argo WorkflowTemplates
 ├── {workflow-name}.yaml
@@ -59,6 +65,29 @@ kuberay-images/              # GPU worker images
 
 ## Python Conventions
 
+### Package Management (ADR-0012)
+
+Use **uv** for local development and **pip** in Docker for reproducibility:
+
+```bash
+# Install uv (one-time)
+curl -LsSf https://astral.sh/uv/install.sh | sh
+
+# Create virtual environment and install
+uv venv
+source .venv/bin/activate
+uv pip install -e ".[dev]"
+
+# Or use uv sync with lock file
+uv sync
+
+# Update lock file after changing pyproject.toml
+uv lock
+
+# Run tests
+uv run pytest
+```
+
 ### Project Structure
 
 ```python