feat: Initial project scaffold

Flask API backend for ESP32 sensor fleet:
- App factory pattern with blueprints
- SQLAlchemy 2.x models (Sensor, Device, Sighting, Alert, Event, Probe)
- UDP collector for sensor data streams
- REST API endpoints for sensors, devices, alerts, events, probes, stats
- pytest setup with fixtures
- Containerfile for podman deployment
- Makefile for common tasks

pyproject.toml

@@ -0,0 +1,38 @@
+[project]
+name = "esp32-web"
+version = "0.1.0"
+description = "REST API backend for ESP32 sensor fleet"
+requires-python = ">=3.11"
+dependencies = [
+    "flask>=3.0",
+    "flask-sqlalchemy>=3.1",
+    "flask-migrate>=4.0",
+    "flask-cors>=4.0",
+    "gunicorn>=21.0",
+    "python-dotenv>=1.0",
+]
+
+[project.optional-dependencies]
+dev = [
+    "pytest>=8.0",
+    "pytest-cov>=4.0",
+    "ruff>=0.1",
+]
+
+[build-system]
+requires = ["setuptools>=68"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools.packages.find]
+where = ["src"]
+
+[tool.ruff]
+line-length = 100
+target-version = "py311"
+
+[tool.ruff.lint]
+select = ["E", "F", "I", "W"]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+pythonpath = ["src"]