The page's script is TypeScript in web/src, built and minified with swc

- web/src/*.ts: the script that was inline in index.html and login.html, split along its
  existing sections. Still one scope, concatenated in order, not modules.
- web/build.mjs strips the types, puts the script in the page and minifies it with swc;
  build.rs runs it into OUT_DIR and web.rs include_str!s the result. 137 KB -> 106 KB.
- npx tsc -p . type-checks web/src, loosely; the handful of annotations it needed
  change no behaviour.
- The Docker build installs node and swc (npm ci --omit=dev).
- Two list requests racing no longer let the older one win, and switching tabs clears
  the selection it closes, which made a browser test flaky.

Closes #23, #24.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Dockerfile

@@ -1,17 +1,23 @@
 # Build. rusqlite is bundled (compiles SQLite from source) and librqbit needs a C
 # toolchain, so the builder needs cc. TLS is rustls throughout, so no OpenSSL headers.
+# build.rs builds the web pages from TypeScript with swc, which needs node.
 FROM rust:1-slim-bookworm AS build
 RUN apt-get update && apt-get install -y --no-install-recommends \
-        build-essential \
+        build-essential nodejs npm \
     && rm -rf /var/lib/apt/lists/*
 WORKDIR /src
 
+# swc only: Playwright and TypeScript are for testing and type-checking, not for building.
+COPY package.json package-lock.json ./
+RUN npm ci --omit=dev
+
 # Dependencies first, so editing the source does not rebuild librqbit every time.
 COPY Cargo.toml Cargo.lock ./
 RUN mkdir src && echo 'fn main(){}' > src/main.rs \
     && cargo build --release --locked \
     && rm -rf src
 
+COPY build.rs ./
 COPY src ./src
 COPY web ./web
 # cargo skips a rebuild if mtimes look untouched; make sure it does not.