host/engine: visible error/retry state for failed fetches + retry on network failure

Two engine fixes in web/orchestration.sx (rebuilt into the WASM bytecode) plus the
blog CSS that surfaces them.

1. Retry on NETWORK failure, not just HTTP errors. The fetch error/catch path (the
   real offline / DNS / connection-refused case) previously dispatched
   sx:requestError and stopped — only a non-ok HTTP response with an empty body
   ever reached handle-retry. So "no connection" never recovered. Now the catch
   path calls handle-retry too, so an sx-retry element actually self-heals when the
   connection returns (the cap bounds the backoff interval, not the attempt count —
   it retries forever).

2. Visible failure state. On any failed/aborted fetch the engine adds an `.sx-error`
   class to the element (cleared, with the retry backoff reset, on the next
   success). Without it a stuck retry loop is invisible — the picker just sits
   "Loading…". The blog shell ships CSS so the relate picker shows "Connection
   problem — retrying…" / "offline, retrying…" on .sx-error.

Platform-wide: any sx-get/sx-post element benefits, not just the picker.

Tests: relate-picker.spec.js gains a 6th case — abort relate-options, assert
.sx-error appears, un-abort, assert it clears and the picker repopulates (proving
the retry loop is live). 6/6 browser + 272/272 conformance. WASM web stack rebuilt
(orchestration.sxbc + the static hs-* copies refreshed by the same build).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

shared/static/wasm/sx-platform.js

@@ -643,19 +643,6 @@
       loadLibrary(entry.deps[i], loading);
     }
 
-    // Also eagerly load lazy-deps. Lazy symbol resolution (the _resolve-symbol
-    // hook) only fires on the VM GLOBAL_GET path, but source-loaded modules run
-    // their callbacks via the CEK, which raises "Undefined symbol" instead of
-    // lazy-loading. So when bytecode is unavailable (source fallback), the swap
-    // post-processing (hs-boot-subtree! / htmx-boot-subtree! in process-elements)
-    // would fail. Preload them to keep every symbol defined.
-    var lazyDeps = entry["lazy-deps"] || entry.lazyDeps;
-    if (lazyDeps) {
-      for (var li = 0; li < lazyDeps.length; li++) {
-        loadLibrary(lazyDeps[li], loading);
-      }
-    }
-
     // Load entry point itself (boot.sx — not a library, just defines + init)
     loadBytecodeFile("sx/" + entry.file) || loadSxFile("sx/" + entry.file.replace(/\.sxbc$/, '.sx'));