fix: honour dashboard rebase for edited branch with no open PR

[pose]

Changes

The Dependency Dashboard's PR Edited (Blocked) checkbox is silently ignored for an edited branch with no open PR: the else if (branchIsModified) block in processBranch() returns pr-edited without consulting dependencyDashboardCheck, unlike every other early return in that function. The dashboard re-renders the branch in the same list with the box unticked, so the request can never take effect.

Skipping that block when a dashboard check is present lets the flow reach userRebaseRequested, which sets reuseExistingBranch = false and recreates the branch from base, as the section's text promises.

Context

Please select one of the following:

• This closes an existing Issue, Closes: #
• This doesn't close an Issue, but I accept the risk that this PR may be closed if maintainers disagree with its opening or implementation

AI assistance disclosure

Did you use AI tools to create any part of this pull request?

• No — I did not use AI for this contribution.
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• Yes — substantive assistance (AI-generated non-trivial portions of code, tests, or documentation).
• Yes — other (please describe):

Claude Opus 4.8, via Claude Code: the code change, the two unit tests, and this description. Human-reviewed before submission.

Documentation (please check one with an [x])

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I have verified these changes via:

• Code inspection only, or
• Newly added/modified unit tests, or
• No unit tests, but ran on a real repository, or
• Both unit tests + ran on a real repository

[cla-assistant]

All committers have signed the CLA.

[pose]

For transparency: I force-pushed this branch a few times while it was still in draft, to fix the commit message and author email. No commits have been amended since it was marked ready for review, and I won't rebase from here.