fix: allow WebAssembly in the CSP so xz sidecars can be decoded

The xz decompressor for Instaloader's .json.xz sidecars is WebAssembly,
embedded as a data: URL that it fetches at startup. The CSP added in 1.3.0
blocked both halves of that:

  fetch('data:application/wasm;...')  -> TypeError: Failed to fetch
  WebAssembly.instantiate(...)        -> CompileError: violates script-src 'self'

The first surfaces through new Response(stream).json() as a bare "Failed to
fetch" with no stack, which reads like a network fault and is why this was
mis-diagnosed twice. Vite's dev server never sends the CSP, so it reproduced
only in production — every Instaloader archive silently lost its captions,
story flags and profile metadata from 1.3.0 onward.

script-src now allows 'wasm-unsafe-eval', which permits WebAssembly compilation
without permitting eval() of JavaScript, and connect-src allows data: for the
embedded module.

Verified against the production bundle: rivvsofficial goes from 188 posts / 0
followers / no stories to 68 posts, 120 stories, 10,337 followers and its real
name, bio and link — with zero decode errors.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011uBWhwV3wFQ5MBCcMHHem7

server.ts

@@ -80,10 +80,16 @@ app.use((req, res, next) => {
     "default-src 'self'",
     "img-src 'self' blob: data:",
     "media-src 'self' blob: data:",
-    "script-src 'self'",
+    // 'wasm-unsafe-eval' permits WebAssembly compilation without allowing
+    // eval() of JavaScript. The xz decompressor used for Instaloader's
+    // .json.xz sidecars is WebAssembly, embedded as a data: URL it fetches at
+    // startup — so connect-src must allow data: too. Without both, decoding
+    // fails with a bare "TypeError: Failed to fetch" and every archive silently
+    // loses its captions, story flags and profile metadata.
+    "script-src 'self' 'wasm-unsafe-eval'",
     "style-src 'self' 'unsafe-inline'",
     "font-src 'self'",
-    "connect-src 'self'",
+    "connect-src 'self' data:",
     "worker-src 'self' blob:",
     "frame-ancestors 'self'",
     "object-src 'none'",