feat: scaffold initial DevPlace project with FastAPI, SQLite auth, and SSR routing

Add complete project skeleton including .gitignore, Makefile, AGENTS.md, config, database init with indexes, main app with router mounting for auth/feed/posts/comments/projects/profile/messages/notifications/votes, Pydantic models for signup/login/post/comment/project/message/profile, and auth router with signup/login page rendering and form handling.

Makefile

@@ -0,0 +1,22 @@
+.PHONY: install dev clean test test-headed demo
+
+install:
+	pip install -e .
+
+dev:
+	uvicorn devplacepy.main:app --reload --host 0.0.0.0 --port 10500
+
+test:
+	PLAYWRIGHT_HEADLESS=1 python -m pytest tests/ -v --tb=line
+
+test-headed:
+	PLAYWRIGHT_HEADLESS=0 python -m pytest tests/ -v --tb=line
+
+demo:
+	PLAYWRIGHT_HEADLESS=0 python -m pytest tests/test_demo.py -v -s
+
+clean:
+	find . -type d -name __pycache__ -exec rm -rf {} + 2>/dev/null || true
+	find . -type f -name '*.pyc' -delete
+	rm -rf devplacepy.egg-info
+	rm -rf .venv