chore: remove the Python service; Python is the training stack only

Phase 4 of docs/RUST_REWRITE.md. Since 2026-10-18 ping-collector (rust/)
collects, forecasts, notifies (ntfy + Matrix) and serves the website/API;
nothing in production ran the Python service code any more.

Removed (~17k lines): the FastAPI app (web_api, schemas, health_check,
metrics, postgres_history, forecast_history, thaiwater), the Python RID
collector and CLI (water_scraper_v3, main, run.py), the notifier and Matrix
alerting (notify, alerting), the multi-backend adapters (SQLite, MySQL,
InfluxDB, VictoriaMetrics) with demo databases, models/validators/exceptions/
logging/rate limiter, ml/skill.py (served by Rust now), the migration tooling
(api_parity, collector_parity, e2e_notify, install_collector.sh,
gen_notify_cases.py, spikes/rust-forecast), Docker/compose/Grafana files,
sql/, the release workflow and the docs for all of that. Their tests went
with them.

Kept in Python: src/ml (training, evaluation harness, export; predict.py as
the reference the Rust forecaster is tested against), the HII and RID-dam
clients/stores for the archive backfills (their live collectors removed),
the backfill scripts, retrain.sh + timer, forecast_parity.py.

- PostgreSQL only: src/config.py is database_url() from POSTGRES_* / .env;
  the stores lost their sqlite/mysql branches (and the 2026-08 column
  migration). The database tests run against a throwaway schema from
  TEST_DATABASE_URL (tests/conftest.py pg_url, skipped without it), as the
  Rust tests do; CI gets a PostgreSQL service. 100 tests (66 without a DB).
- The notifier settings moved from src/notify.py into src/ml/export.py;
  flood_config.json regenerates byte-identical.
- tests/test_dashboard.py checks every path the dashboard fetches against
  ping-collector's router.
- Dependencies: fastapi, uvicorn, pydantic, influxdb, pymysql, psutil,
  schedule, sphinx, pyinstaller, mypy, pytest-asyncio dropped; python-dotenv
  1.1.1 explicit (it came in through uvicorn[standard]).
- Formatting contract extended to scripts/ and tests/ (reformatted once).
- scripts/install.sh is the one installer (fresh host or update, in place in
  a checkout without touching its ownership): binary, units, uv sync, .env
  defaults, removes the retired water-monitor.service and any old
  --alert-check cron job, dry run + forecast check, restart, readiness wait.
- Docs, CLAUDE.md, CONTRIBUTING.md, .env.example, Makefile, unit comments
  and Rust doc comments updated to the Rust service.

Makefile

@@ -1,181 +1,70 @@
-# Northern Thailand Ping River Monitor - Makefile
+# Ping River Monitor. The service is Rust (rust/, ping-collector); Python is
+# the model training/evaluation stack and the archive backfills (src/).
+# Database tests (both sides) need TEST_DATABASE_URL, e.g.
+#   docker run -d --name ping-pg -e POSTGRES_PASSWORD=ping -e POSTGRES_DB=ping -p 55432:5432 postgres:16
+#   export TEST_DATABASE_URL=postgres://postgres:ping@localhost:55432/ping
 
-.PHONY: help install install-dev test test-coverage lint format clean run run-api docker-build docker-run docs
+PY_SRC := src/ scripts/ tests/ rust/forecast/testdata rust/collector/testdata
+CARGO := cargo
+MANIFEST := --manifest-path rust/Cargo.toml
+
+.PHONY: help install format lint test test-py test-rust build check serve train evaluate export clean
 
-# Default target
 help:
-	@echo "Northern Thailand Ping River Monitor - Available Commands:"
-	@echo ""
-	@echo "Setup:"
-	@echo "  install      Install production dependencies"
-	@echo "  install-dev  Install development dependencies"
-	@echo ""
-	@echo "Development:"
-	@echo "  test         Run all tests"
-	@echo "  test-cov     Run tests with coverage report"
-	@echo "  lint         Run code linting"
-	@echo "  format       Format code with black and isort"
-	@echo "  clean        Clean up temporary files"
-	@echo ""
-	@echo "Running:"
-	@echo "  run          Run the monitor in continuous mode"
-	@echo "  run-api      Run the web API server"
-	@echo "  run-test     Run a single test cycle"
-	@echo "  run-status   Show system status"
-	@echo ""
-	@echo "Alerting:"
-	@echo "  alert-check  Check water levels and send alerts"
-	@echo "  alert-test   Send test Matrix message"
-	@echo ""
-	@echo "Distribution:"
-	@echo "  build-exe    Build standalone executable"
-	@echo "  package      Build and create distribution package"
-	@echo ""
-	@echo "Docker:"
-	@echo "  docker-build Build Docker image"
-	@echo "  docker-run   Run with Docker Compose"
-	@echo "  docker-stop  Stop Docker services"
-	@echo ""
-	@echo "Database:"
-	@echo "  setup-postgres Setup PostgreSQL database"
-	@echo "  test-postgres  Test PostgreSQL connection"
-	@echo "  encode-password URL encode password for connection string"
-	@echo "  migrate-sqlite Migrate SQLite data to PostgreSQL"
-	@echo "  migrate-fast   Fast migration with 10K batch size"
-	@echo "  analyze-sqlite Analyze SQLite database structure (dry run)"
-	@echo ""
-	@echo "Documentation:"
-	@echo "  docs         Generate documentation"
+	@echo "make install    uv sync (Python 3.11) + pre-commit hooks"
+	@echo "make format     black + isort (Python), cargo fmt (Rust)"
+	@echo "make lint       the CI checks without tests (format, flake8, clippy)"
+	@echo "make test       pytest + cargo test"
+	@echo "make build      release build of ping-collector (rust/target/release)"
+	@echo "make check      lint + test + the Rust 1.88 minimum-version check"
+	@echo "make serve      website/API from the local database on 127.0.0.1:8001"
+	@echo "make train      retrain every station's model into models/"
+	@echo "make evaluate   rolling-origin harness on P.1 (see scripts/evaluate_variants.py)"
+	@echo "make export     export trained models + flood_config.json for the Rust forecaster"
 
-# Installation
 install:
-	uv sync --no-dev
-
-install-dev:
-	uv sync
+	uv sync --python 3.11
 	uv run pre-commit install
 
-# Testing
-test:
+format:
+	uv run black $(PY_SRC)
+	uv run isort src/ scripts/ tests/
+	$(CARGO) fmt --all $(MANIFEST)
+
+lint:
+	uv run black --check $(PY_SRC)
+	uv run isort --check-only src/ scripts/ tests/
+	uv run flake8 src/ scripts/ tests/ --count --select=E9,F63,F7,F82 --show-source --statistics
+	$(CARGO) fmt --all --check $(MANIFEST)
+	$(CARGO) clippy --all-targets --locked $(MANIFEST) -- -D warnings
+
+test: test-py test-rust
+
+test-py:
 	uv run pytest -q
 
-test-cov:
-	uv run pytest --cov=src --cov-report=html --cov-report=term
+test-rust:
+	$(CARGO) test --locked $(MANIFEST)
 
-# Code quality
-lint:
-	uv run flake8 src/ --max-line-length=100
-	uv run mypy src/
+build:
+	$(CARGO) build --release --locked $(MANIFEST)
 
-format:
-	uv run black src/ *.py
-	uv run isort src/ *.py
+check: lint test
+	CARGO_TARGET_DIR=rust/target/msrv $(CARGO) +1.88 check --all-targets --locked $(MANIFEST)
+
+serve:
+	rust/target/release/ping-collector serve --listen 127.0.0.1:8001 --no-analytics
+
+train:
+	uv run python scripts/train_flood_model.py --stations all
+
+evaluate:
+	uv run python scripts/evaluate_variants.py --stations P.1
+
+export:
+	uv run python -m src.ml.export
+	uv run python -m src.ml.export --config
 
-# Cleanup
 clean:
-	find . -type f -name "*.pyc" -delete
-	find . -type d -name "__pycache__" -delete
-	find . -type f -name "*.log" -delete
-	rm -rf .pytest_cache/
-	rm -rf .mypy_cache/
-	rm -rf htmlcov/
-	rm -rf dist/
-	rm -rf build/
-	rm -rf *.egg-info/
-
-# Running
-run:
-	uv run python run.py
-
-run-api:
-	uv run python run.py --web-api
-
-run-test:
-	uv run python run.py --test
-
-run-status:
-	uv run python run.py --status
-
-# Alerting
-alert-check:
-	uv run python run.py --alert-check
-
-alert-test:
-	uv run python run.py --alert-test
-
-# Docker
-docker-build:
-	docker build -t ping-river-monitor .
-
-docker-run:
-	docker-compose -f docker-compose.victoriametrics.yml up -d
-
-docker-stop:
-	docker-compose -f docker-compose.victoriametrics.yml down
-
-docker-logs:
-	docker-compose -f docker-compose.victoriametrics.yml logs -f
-
-# Documentation
-docs:
-	cd docs && make html
-
-# Monitoring
-health-check:
-	curl -f http://localhost:8000/health || exit 1
-
-metrics:
-	curl -s http://localhost:8000/metrics | jq .
-
-# Development helpers
-dev-setup: install-dev
-	cp .env.example .env
-	@echo "Development environment set up!"
-	@echo "Edit .env file with your configuration"
-
-# Production deployment
-deploy-check:
-	uv run python run.py --test
-	@echo "Deployment check passed!"
-
-# Database management
-setup-postgres:
-	uv run python scripts/setup_postgres.py
-
-test-postgres:
-	uv run python -c "from scripts.setup_postgres import test_postgres_connection; from src.config import Config; config = Config.get_database_config(); test_postgres_connection(config['connection_string'])"
-
-migrate-sqlite:
-	uv run python scripts/migrate_sqlite_to_postgres.py
-
-migrate-fast:
-	uv run python scripts/migrate_sqlite_to_postgres.py --fast
-
-analyze-sqlite:
-	uv run python scripts/migrate_sqlite_to_postgres.py --dry-run
-
-# Git helpers
-git-setup:
-	git remote add origin https://git.b4l.co.th/B4L/Northern-Thailand-Ping-River-Monitor.git
-	@echo "Git remote configured!"
-
-# Quick start
-quick-start: install dev-setup run-test
-	@echo "Quick start completed!"
-	@echo "Run 'make run-api' to start the web interface"
-
-# Gitea Actions
-validate-workflows:
-	@echo "Validating Gitea Actions workflows..."
-	@for file in .gitea/workflows/*.yml; do \
-		echo "Checking $$file..."; \
-		uv run python -c "import yaml; yaml.safe_load(open('$$file', encoding='utf-8'))" || exit 1; \
-	done
-	@echo "✅ All workflows are valid"
-
-workflow-test:
-	@echo "Testing workflow components locally..."
-	make test
-	make lint
-	make format
-	@echo "✅ Workflow test completed"
+	find . -type d -name "__pycache__" -prune -exec rm -rf {} +
+	rm -rf .pytest_cache/ htmlcov/ dist/ build/ *.egg-info/