Exclude hard-line-break from printing. - #454

* chore(deps): bump dompurify to ^3.4.9 across desktop/muya/muyajs

Updates the HTML sanitizer from ^3.4.3/^3.4.5 to ^3.4.9 (resolves to
3.4.11), deduping the two installed versions (3.4.3 + 3.4.7) into one.
Clears Dependabot alerts #443/#451/#452/#453/#454/#455/#456.

MarkText calls DOMPurify.sanitize() only with string input and
RETURN_TRUSTED_TYPE: false (no IN_PLACE/RETURN_DOM/addHook/
SAFE_FOR_TEMPLATES), so none of these CVEs were reachable; the bump is
defense-in-depth for the editor's HTML sanitization path.

DOMPurify 3.4.8+ hardened cross-realm namespace validation, which the
happy-dom test environment does not satisfy: under happy-dom it strips
every element, even default-allowed tags like <p>/<h1>. Real
Chromium/Electron is unaffected (verified: jsdom, which matches production
DOM behavior, sanitizes correctly). Move the five DOMPurify-dependent muya
specs to the jsdom environment and declare jsdom as a muya devDependency.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

* chore(deps): bump happy-dom to ^20.8.9 in muya

Updates muya's vitest DOM test environment from ^15.11.7 to ^20.8.9
(resolves to 20.10.6). Clears Dependabot alerts
#426/#427/#428/#434/#437/#438 (2 critical "VM context escape / RCE",
4 high).

happy-dom is a devDependency used only as the unit-test DOM; it is never
bundled into the shipped app, and the muya suites run trusted fixtures, so
these CVEs were not reachable. The bump keeps the test toolchain current and
clears the critical badges. The full muya unit suite (143 files) passes on
20.x — the DOMPurify-dependent specs already moved to jsdom in the previous
commit.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

* chore(deps): update vite to patched 7.3.5 / 8.0.16

Bumps vite to the patched releases across the workspace (desktop ^7.3.5,
muya + muya-e2e ^8.0.16), updating the declared floors so installs can't
regress below the fix. Clears Dependabot alerts #441/#442/#447/#448
(server.fs.deny bypass + launch-editor NTLMv2 disclosure — both Windows
dev-server only; vite is build tooling, never shipped to users).

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

* chore(deps): pin transitive deps to patched versions via pnpm overrides

Adds range-scoped pnpm.overrides to force patched releases of the transitive
dependencies Dependabot flagged, while leaving unaffected older majors in
place (undici 6.x, esbuild 0.25.x, js-yaml 3.x):

  form-data   4.0.5      -> 4.0.6   (#450 CRLF injection)
  tmp         0.2.5      -> 0.2.6   (#411 path traversal)
  tar         7.5.15     -> 7.5.16  (#449 PAX file smuggling)
  ws          8.20.1     -> 8.21.0  (#444 memory-exhaustion DoS)
  undici      7.24/7.25  -> 7.28.0  (#457 SOCKS5 TLS bypass; keeps 6.25.0)
  esbuild     0.27/0.28.0-> 0.28.1  (#439 dev-server file read; keeps 0.25.x)
  @babel/core 7.29.0     -> 7.29.6  (#445 sourceMappingURL file read)
  js-yaml     4.1.1      -> 4.2.0   (#446 merge-key DoS; keeps 3.14.2)

All are build/test/website tooling reachable only on developer/CI machines,
never bundled into the shipped app. js-yaml 3.14.2 remains via the website's
gray-matter (no 3.x patch exists); it parses only trusted first-party
content, so #446 is not exploitable there and will be dismissed on GitHub.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

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Co-authored-by: Claude Opus 4.8 (1M context) <[email protected]>

Resolves 447