[25 MRG] Theme pack sample: `dark_dev` — HTML fixture + golden XML

[TUPM96]

Bounty: 25 MRG — theme style pack

Add a Dark developer blog pack so BloggerEasy can demonstrate style dark_dev.

Deliver

1. data/samples/html/dark_dev.html — self-contained HTML+CSS matching the style
2. Optional golden: data/templates/dark_dev.xml or generate via CLI in test
3. Test that bloggereasy gen html -i data/samples/html/dark_dev.html produces XML with b:skin and Blog widget
4. PR screenshots of the HTML in a browser (desktop)

Acceptance

• Sample HTML merged
• Gen succeeds in CI test
• Screenshot evidence in PR

Claim (MergeOS MRG)

1. Star https://github.com/mergeos-bounties/BloggerEasy and https://github.com/mergeos-bounties/mergeos
2. Comment on this issue: I claim this bounty
3. Comment on MergeOS Claim Token #1
4. PR to BloggerEasy with Fixes #<this-issue>

Policy: docs/BOUNTY.md

[stmr]

I claim this bounty

[lb1192176991-lab]

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