feat(mvp): phase 1 - project scaffolding & tooling

Initialize SvelteKit project with Svelte 5, TypeScript strict, Tailwind CSS v4,
shadcn-svelte, Prisma + SQLite, Vitest, ESLint, Prettier. Add Docker multi-stage
build, docker-compose, and Gitea Actions CI pipeline.

.prettierrc

@@ -0,0 +1,15 @@
+{
+	"useTabs": true,
+	"singleQuote": true,
+	"trailingComma": "none",
+	"printWidth": 100,
+	"plugins": ["prettier-plugin-svelte", "prettier-plugin-tailwindcss"],
+	"overrides": [
+		{
+			"files": "*.svelte",
+			"options": {
+				"parser": "svelte"
+			}
+		}
+	]
+}