Initial project scaffold: FastAPI backend + Svelte 5 frontend

Backend (uv): FastAPI app with routers (foods, log, targets, OFF proxy),
SQLAlchemy models, Pydantic schemas, migration runner + 0001 initial schema,
example pytest suite (7 tests).
Frontend (npm): Vite 7 + Svelte 5 runes, lib/ (api, stores, scanner, format)
per spec §7, placeholder components, example vitest suite (4 tests).
SPEC.md §1: registered uvicorn and Vitest (rule §8.3.3).

.gitignore

@@ -0,0 +1,17 @@
+# Python / uv
+__pycache__/
+*.pyc
+.venv/
+
+# App data
+*.db
+
+# Node / Vite
+node_modules/
+dist/
+
+# OS / editor
+.DS_Store
+
+# pi agent session files
+.pi/