The bug

The "Part of Main template — double-click to edit" hover hint fired over the entire page — including the active page's own editable content (e.g. the ABOUT heading), not just the template chrome (header/footer). Worse, double-clicking that editable content opened the template instead of editing the node — which silently breaks inline text editing on any page that has a wrapping template.

Root cause

The active document's editable content is spliced into the wrapping template's base.outlet (CanvasComposedTree), so in the DOM it lives inside the read-only wrapper element. That wrapper carries data-instatic-readonly-* markers (it's template chrome). Both consumers resolved the region by walking straight up:

target.closest('[data-instatic-readonly-label]')   // hover hint (BreakpointFrame)
target.closest('[data-instatic-readonly-id]')      // double-click open (IframeFrameSurface)

So they found the wrapper ancestor and treated the editable page content as read-only — even though editable nodes carry their own data-node-id and never the read-only markers (the two are mutually exclusive). The "another wrapper" intuition was exactly right.

The fix

A shared closestReadonlyRegion(target) resolves the nearest boundary of either kind — [data-node-id] (editable) or [data-instatic-readonly-label] (read-only). An editable node nearer than any read-only marker means the target is the active page's own content, so: no hint, no template-open. Wired into both the hover hint and the double-click-to-open, and dedups the cross-realm isElementLike helper that was copied in both files.

Tests

New closestReadonlyRegion unit tests cover the exact bug (editable node spliced inside a read-only wrapper → no region), plus read-only chrome, unmarked chrome children, plain editable nodes, and non-element targets. bun test (full), bun run build, bun run lint all green.

Verified the boundary logic via the unit tests + reading the composition path. A quick manual check in an environment with a wrapping template is worth doing: hover page content → no hint; hover header/footer → hint; double-click a page heading → inline-edit (not "open template").

🤖 Generated with Claude Code