Setting location.hash inside a vault app re-navigates the frame: every link silently dead

OpenHighFailuredev.vault.sgraph.ai

What we saw

In the host the app is an about:srcdoc frame, where assigning location.hash re-navigates instead of firing hashchange. The How Much Evidence vault shipped on 5 October 2026 with every view link dead.

Why it matters

An app that works when opened as a file ships to readers with no working navigation, and nothing errors.

The fix

Keep the route in a variable; catch a[href^="#"] in a capture click handler; mark links data-sg-native; use the hash only when running standalone. Documented in the sgit.ai guidance.

The record

Status	Open. Open as a platform trap; every lab vault avoids it.
Severity	High
Kind	Failure: works against the reader
Product	dev.vault.sgraph.ai, platform
Where	any vault app that routes by hash
Problems	Host trap, Dead end
Visibility	Silent: no symptom on screen: found only by measuring, or by its consequences
Recommendation	Design for the host: use the host's own mechanisms (route variable, sg.state, vault snapshot) instead of the browser's defaults
Area	Platform
Breaks	A vault app works inside the host, not just on its own
Observed	2026-10-05, host
Last checked	2026-10-11, host
Source	Design lab: what building it measured

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