feat(templates): link SerifHeadline titles and keep its band columns off the rule

[DemchaAV]

Why

Three things the rendered sheet showed once it existed.

A project card wants to point somewhere — a repository, a case study — and nothing in the model could say so. A band column's text ran into the hairline beside it, because the published sheet lets it: a line that happens to fill its column touches the rule. And the packaged marks come in two colours, which nothing said, so the example mixed a navy project mark with a gold one and the row read as a mistake.

What changed

• CvEntry carries a link. A plain string, blank when absent, set through CvEntry.Builder.link(...). Every title SerifHeadline draws — a role, a project, a degree, an achievement — becomes a link when its entry carries one. The six-argument constructor is kept explicitly.
• Band columns keep a gutter at their right edge, so the text stops short of the separator instead of running into it. The gutter matches GLYPH_CLEARANCE, the space the next column's mark already keeps on the other side, so the rule sits centred in white.
• The class documentation names the two mark colours — cart and api in the design's navy, trophy, chart and rocket in its gold — so a document picks one deliberately. The example now keeps its projects band to one colour and links both cards.

Verification

Full reactor gate → BUILD SUCCESS; the serif and CV-data suites 21/21; examples suite 77/77 including CommittedAssetDriftTest with the re-rendered preview; javadoc:javadoc → BUILD SUCCESS.

This is the first place a promoted preset deliberately leaves the sheet it ports, so the departure is measured rather than described. Against the published template's own render, the fixture now differs by:

• 6 of 235 nodes, all of them narrowed by the gutter — three card texts and their containers. Every other node is identical on path and geometry.
• 8 191 of 2 173 720 pixels (0.38%), which is those three columns rewrapping.

Both baselines were re-recorded with the change and nothing else moved — the working tree after the approve run shows only this preset's two files.

The link costs nothing by comparison: it is an annotation rather than ink, so it moves no pixel and no layout node. That is also why neither gate can protect it, and a smoke case asserts the three targets directly.

Notes

• The gutter is uniform across a band, including the last column, so the columns stay equal width. Making the last one wider would have bought a few points of measure at the cost of the thing the eye actually reads.
• The link is drawn on every title rather than only on projects: a document that puts a URL on a role would otherwise lose it silently, which is the failure mode this campaign keeps finding.

Lane: canonical (templates.cv.data + templates.cv.presets + qa + examples) — no engine changes.