[SAMARTHJAISWAL]

Description

Fixes #15311.

The Typst format passes the document logo through fillLogoPaths() before resolveLogo(). resolveLogo() already treats false as "no logo" (since #13922), but fillLogoPaths() turned every falsy value into undefined first. resolveLogo() then fell back to the brand's small/medium/large logo, and the page.typ partial drew it as the page background on every page.

This makes fillLogoPaths() return false unchanged, as the issue suggests, so logo: false reaches resolveLogo(). fillLogoPaths() is only called from the Typst format, and its return type already allows false.

Tested:

• New smoke tests tests/docs/smoke-all/brand/logo/typst-logo-false-format.qmd (logo: false under typst) and typst-logo-false-top.qmd (logo: false at the top level). Both use a brand with a small logo and a primary colour, and check that the .typ output has no set page(background and draws no logo image, while the brand colour is still there. Both fail on main and pass with this change.
• All smoke tests under tests/docs/smoke-all/brand/logo/ pass locally (159 passed).

Checklist

I have (if applicable):

• referenced the GitHub issue this PR closes
• updated the appropriate changelog in the PR
• ensured the present test suite passes
• added new tests
• created a separate documentation PR in Quarto's website repo and linked it to this PR (not needed, bug fix only)

AI-assisted PR

• AI tool used: Claude Code
• Codebase grounding: local clone
• Human review: I have reviewed, tested, and verified the AI-generated content before submitting.

[posit-snyk-bot]

✅ Snyk checks have passed. No issues have been found so far.

Status	Scan Engine	Critical	High	Medium	Low	Total (0)
✅	Open Source Security	0	0	0	0	0 issues
✅	Licenses	0	0	0	0	0 issues

💻 Catch issues earlier using the plugins for VS Code, JetBrains IDEs, Visual Studio, and Eclipse.