fix(french): novhell chapters using Gutenberg template

[Balrog57]

Checklist

• Update version code if an existing plugin was modified (1.0.4 -> 1.0.5)
• Test changes in Plugin Playground or the app (see Tests)
• Commit messages follow type(scope): description

Bug

Opening some Tempest of the Stellar War chapters (e.g. 251, 252) fails with \No readable chapter content found, while the same pages render fine in the WebView.

Root cause

Those chapter pages use a WordPress Gutenberg block template (\�rticle .entry-content\ with .wp-block-columns\ children, zero \section\ elements) instead of the classic \main article div div section\ layout. \parseChapter\ only handled the classic layout, found no sections, and threw. Classic chapter pages (e.g. ch. 250: 5 sections, title \h4\ + body) are unaffected.

Fix

• \plugins/french/novhell.ts: keep the classic section heuristic first (unchanged); on miss, fall back to the Gutenberg layout - title from the columns block holding the \h4, body from the longest columns block - with the same >=200-chars-or-image validation.

Tests

• Before: /tsw-chapitre-251/\ and /tsw-chapitre-252/\ threw \No readable chapter content found.
• After: 251 OK (14990 chars, starts with chapter title), 252 OK (10179 chars); classic chapters byte-identical results (250, tsw-1, sws-1 verified).
• Full audit of all 5 novels (1758 chapters): zero parse failures remaining. The only 4 errors are site-side HTTP 404s on typo'd links the plugin cannot fix: \ sw-chapitre-1781, \jtsw-chapitre-386\ (should be \ sw-), \ tob-chapitre-58\ (should be \ otb-), \srh-chapitre-360-2\ (wrong-novel prefix inside Swallowed Star).
• Live-check harness: all PASS (popular 5, search 1, parseNovel 393 chapters, parseChapter 15805 chars); eslint and ES5 production \ sc\ clean.