style: reduce main header max-width to standard container size

[HarshMN2345]

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[greptile-apps]

Greptile Summary

This PR reduces the main header wrapper's max-inline-size from the hard-coded pxToRem(1728) to the design token var(--container-size-normal) (1200 px), bringing it in line with the standard container width. It also refactors the extended-borders-footer::before pseudo-element on the init page to extend the dashed border edge-to-edge by using left: -100%; right: -100% after removing the previous overflow: hidden guard.

• The removal of overflow: hidden and max-width: 100vw from .extended-borders-footer without a confirmed parent-level overflow clip risks introducing a horizontal scrollbar at all viewport widths where the pseudo-element extends beyond the viewport.

Confidence Score: 4/5

Safe to merge after verifying the horizontal overflow concern in the init page footer.

One P1 finding: removing overflow: hidden from .extended-borders-footer while the ::before pseudo-element now spans left: -100%; right: -100% may introduce a horizontal scrollbar unless a parent element already clips overflow. The SCSS change itself is clean and low-risk.

src/routes/(init)/init/+page.svelte — the extended-borders-footer overflow guard removal needs verification.

Important Files Changed

Filename	Overview
src/scss/7-components/_main-header.scss	Replaces hard-coded pxToRem(1728) with the design-token var(--container-size-normal) (1200 px), aligning the header wrapper with the standard container width.
src/routes/(init)/init/+page.svelte	Refactors .extended-borders-footer pseudo-element: removes overflow: hidden / max-width: 100vw and extends ::before with left: -100%; right: -100%, which risks horizontal overflow if no ancestor clips it.

_{Reviews (2): Last reviewed commit: "fix init footer" | Re-trigger Greptile}

[greptile-apps]

Potential horizontal overflow after removing overflow: hidden

The original code used overflow: hidden on .extended-borders-footer to clip the absolutely-positioned ::before pseudo-element within the viewport. That guard was removed, but the new left: -100%; right: -100% rule makes ::before extend one full container-width to each side. On a 1200 px container this renders the pseudo-element ~3600 px wide — well beyond the viewport — which will introduce a horizontal scrollbar unless a parent element already sets overflow-x: hidden. Please verify that nothing in the parent chain clips this overflow before shipping.