CANON-041: fix nav-sheet mobile dvh, scroll-lock, and safe-area-inset

[VaultSparkStudios]

What

Three CANON-041.2 violations fixed in nav-sheet.js / nav-sheet.shell-e4e11cde5c.js — the bottom-sheet nav active for ~50% of mobile users (canary ramp).

Fix 1 — 60vh → 60dvh (progressive enhancement)

/* before */
max-height: 60vh;

/* after */
max-height: 60vh;      /* fallback for older browsers */
max-height: 60dvh;     /* true visual viewport on iOS Safari */

On iPhone with the address bar visible, 60vh resolves against the large (retracted) viewport, so the sheet extends into obscured screen space. 60dvh always tracks the actual visible area.

Fix 2 — Body scroll-lock: add lockScroll() / unlockScroll()

openSheet() applied no scroll lock — page content scrolled freely behind the open backdrop. closeSheet() had no release path at all.

Added the same iOS-safe position:fixed pattern already used in nav-toggle.js: save scrollY, set body { position:fixed; top: -<savedY>px; ... } on open, restore and scrollTo on close.

Fix 3 — env(safe-area-inset-bottom) in sheet padding

/* before */
padding: 0.6rem 1.1rem 1.4rem;

/* after */
padding: 0.6rem 1.1rem calc(1.4rem + env(safe-area-inset-bottom, 0px));

On iPhone (home-indicator models), the last nav links were clipped under the gesture bar. The main drawer already used this pattern correctly (style.css line 1924).

Files changed

• assets/nav-sheet.js — source
• assets/nav-sheet.shell-e4e11cde5c.js — deployed asset (all HTML pages reference this hash)

How to verify on mobile

1. Open the site on an iPhone with address bar visible (?nav=sheet to force the sheet cohort, or wait for canary assignment).
2. Tap the hamburger — confirm the sheet does not overflow the visible viewport bottom.
3. With the sheet open, attempt to scroll the page behind the backdrop — confirm it does not scroll.
4. Close the sheet (backdrop tap, × button, drag, or Escape) — confirm the page snaps back to the original scroll position.
5. On a home-indicator iPhone (any model ≥ iPhone X), confirm the bottom action buttons are not hidden behind the gesture bar.

Remaining CANON-041 issues (out of scope for this PR)

#	File	Issue
1	command-palette.js:96	height:100vh on mobile palette → 100dvh
5	investor-theme.css:22	min-height:100vh on .inv-page → 100dvh
6	investor-admin.js:408	min-height:100vh on error screen → 100dvh
7	style.css:837	Hamburger 40×40px at 481–980px (min 44px needed)
8	style.css:2401	.pwa-nav-btn ~30px tall (PWA standalone mode)
9	style.css:717	max-height:min(80vh,540px) nav dropdown → dvh
10	style.css:3588	max-height:min(72vh,680px) feedback widget → dvh

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[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Regenerate the fingerprinted nav-sheet asset

Changing assets/nav-sheet.js changes the content hash that scripts/build-shell-assets.mjs uses for the shell filename, but this commit keeps the old nav-sheet.shell-e4e11cde5c.js path and leaves the manifest, service worker, and HTML references stale. I checked node scripts/build-shell-assets.mjs --check, and it now reports drift expecting assets/nav-sheet.shell-e421917c24.js plus updated references, so the build gate will fail and cached visitors can remain on the old sheet code.

Useful? React with 👍 / 👎.

[chatgpt-codex-connector]

Unlock the sheet before same-page navigation

With the new body scroll lock, sheet links that do not unload the document stay stuck behind position:fixed; for example, on /vault-member/, tapping the sheet’s /vault-member/#login or #register actions changes only the hash and no handler calls closeSheet(), so the sheet remains open and closing it later restores savedScrollY instead of the target section. Close/unlock the sheet on same-document link clicks before allowing the anchor navigation.

Useful? React with 👍 / 👎.