Fix initial CI lint failures (cspell, eslint) and add the missing project logo

The first CI pipeline on the 1.x branch (pipeline 840688) reported two lint failures and three functional-test failures, and the logo assets are missing from the branch. This issue covers those fixes for the initial release.

1. cspell

Three legitimate technical terms are flagged as unknown words: macroenabled, ooxml and rclone. They appear in MIME-type strings and the settings-form help text. Add them to .cspell-project-words.txt.

2. eslint

eslint fails on mkdocs.yml line 30 with "Empty mapping values are forbidden" (yml/no-empty-mapping-value). The line uses a Python-specific YAML tag, !!python/name:pymdownx.superfences.fence_code_format, which is valid for MkDocs but not understood by the eslint YAML parser. mkdocs.yml is documentation-tooling configuration, not Drupal code, so it should be excluded from eslint via an .eslintignore entry, mirroring how it is already excluded from prettier.

3. WebDAV returns HTTP 500 on subdirectory installs

Three functional tests fail with HTTP 500. Drupal CI serves the test site under /web, and sabre rejects the request with a LogicException: the requested uri (/web/webdav/...) is "out of base uri" (/webdav/...). The middleware hands sabre the full request URI, which keeps the /web prefix, but builds the sabre baseUri from the hardcoded /webdav prefix without the install's base path. The fix prepends the request base path ($request->getBaseUrl()) to the baseUri so it matches the request URI; the base path is empty on a root install, so root installs are unaffected. The existing functional tests cover the regression.

4. Missing logo assets

Two sets of logo files exist in the working tree but are not yet on the branch:

• logo.png and logo.svg at the project root (for the project page) were not included in the initial 1.x commit.
• docs/logo.png (white header logo) and docs/favicon.png for the documentation site, now wired into mkdocs.yml under the Material theme.

Proposed resolution

• Add macroenabled, ooxml and rclone to .cspell-project-words.txt.
• Exclude mkdocs.yml from eslint.
• Build the sabre baseUri from $request->getBaseUrl() so WebDAV works on subdirectory installs.
• Commit the project-root logo.png / logo.svg and the docs logo.png / favicon.png, with the mkdocs.yml logo and favicon settings.

phpcs, phpstan and composer-lint already pass.