chore(dev): replace devcontainer with uv-based local setup

[vvatelot]

Summary

• Remove the devcontainer workflow and document a lighter local setup based on uv (Python 3.12 via .python-version) and Docker for third-party services
• Replace the Redis container with Valkey in docker-compose and local dev tasks (start-valkey, wait_valkey.py)
• Replace mypy with ty in dev dependencies, quality checks, and VS Code recommendations; add shared .vscode/extensions.json and settings.json

Test plan

• task uv:install installs Python 3.12 and all dependency groups
• task api:init-dev-project initializes the API dev environment
• task api:start-dev starts backend, worker and RQ dashboard with Valkey via Docker
• task quality passes (ty, ruff, pytest)
• docker compose up uses the valkey service instead of redis

Made with Cursor

[github-actions]

Branch coverage •

File	Stmts	Miss	Cover	Missing
bases/ecoindex/cli
arguments_handler.py	84	21	75%	47–52, 54–55, 61–64, 72–73, 78–83, 85
TOTAL	901	273	70%