chore: initial project scaffold

Set up Mangalord with a Rust/axum backend, SvelteKit frontend, Postgres,
and Docker Compose deployment. Establishes the architecture and TDD
patterns the project will extend:

- Hexagonal-ish backend layering (domain / repo / storage / api) with
  a pluggable Storage trait (LocalStorage today, S3 as a future impl).
- Initial migration: users, mangas, chapters, bookmarks.
- Vertical slice for mangas (list, search, create, get) with
  #[sqlx::test] integration coverage and storage unit tests.
- SvelteKit frontend using Svelte 5 runes, typed API client, Vitest
  unit tests and Playwright e2e with route mocking.
- CLAUDE.md documenting layering, TDD/git/SemVer workflow rules, and
  extension points (tags, fulltext search, OCR, S3, auth).
- Project-scoped .claude/settings.json with permission allowlist for
  the toolchain (git, cargo, npm/vite, docker, psql, gh, doc fetches).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/src/main.rs

@@ -0,0 +1,21 @@
+use std::net::SocketAddr;
+use tracing_subscriber::EnvFilter;
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    dotenvy::dotenv().ok();
+    tracing_subscriber::fmt()
+        .with_env_filter(
+            EnvFilter::try_from_default_env().unwrap_or_else(|_| "info,mangalord=debug".into()),
+        )
+        .init();
+
+    let config = mangalord::config::Config::from_env()?;
+    let addr: SocketAddr = config.bind_address.parse()?;
+    let app = mangalord::app::build(config).await?;
+
+    tracing::info!(%addr, "mangalord listening");
+    let listener = tokio::net::TcpListener::bind(addr).await?;
+    axum::serve(listener, app).await?;
+    Ok(())
+}