Replace ember-modal-dialog with native <dialog> and Popover API

[andreisebastianc]

ember-modal-dialog (and its ember-tether/ember-wormhole dependencies) is unmaintained and blocks upgrading consuming apps. The three places that used it now rely on browser primitives instead:

• Search results and the version selector are popover="manual" elements rendered in the top layer and placed next to their anchor with CSS anchor positioning (position-anchor / position-area, with @position-try fallbacks that pin to the viewport edge or flip, like ember-tether's "pin" constraint did). Browsers that support popovers but not anchor positioning (Safari 17/18, Firefox < 147) fall back to inline top/left styles computed from the anchor's bounding box.
• The keyboard shortcuts modal is a native <dialog> opened with showModal(): the browser provides the backdrop, focus trapping, inert page content, Escape handling and (where supported) light dismiss via closedby="any"; a click-on-backdrop fallback covers older browsers.

Behavioural fixes that came with this:

• A long list of versions now scrolls inside the dropdown instead of running off the bottom of the viewport.
• Clicking the search input no longer closes the results and clears the query (the old click-outside handler did not exclude the anchor).
• Escape closes the version selector.
• The dialog close control is a instead of an href="#" link, and the page behind the open dialog no longer scrolls.

[andreisebastianc]

What's this:

I use ember-cli-addon-docs at my workplace. For a long time, it's been clear to me that the addon will have trouble moving to newer ember versions because of several abandoned addons like ember-modal-dialog.

I think simply inlining the addon code is not a good idea, even if other deprecated addons like ember-tether would be inlined at the same time.
The browser provides better primitives than those.

I've made sure to use modifiers instead of did-insert hooks.

This implementation maintains feature parity, for better or worse.

P.S.:

• I couldn't find in the repo a clear stance against contributions done with LLMS
• I wouldn't have had the time to manually do this, but I did review all the work and made significant changes to LLM output by delegating change requests back to the LLM
• The model used is in the commit, and I can produce the prompts

[andreisebastianc]

(ai generated text)

Visual parity

Pixel-compared the dummy app at 1440×900 before/after in Chrome 154: keyboard dialog 0 px differ; version selector 0.02%; search dropdown 0.15%; long version list 0.26%; narrow (480px) version selector 0.22%. The non-zero numbers are 1px text anti-aliasing shifts. Also verified in Firefox 156 and with the JS fallback forced on (same alignment).

Intentional differences:

• A long version list now scrolls inside the dropdown instead of running off the viewport (previously there was no scrollbar).
• Clicking the search input no longer closes the results and clears the query (the old click-outside handler didn't exclude the anchor).
• Escape now closes the version selector.
• The dialog's close control is a <button> instead of an href="#" link, the dialog takes focus when opened (screen readers announce it via aria-labelledby), and the page behind it no longer scrolls.
• When the dialog is taller than the viewport it scrolls internally rather than the overlay scrolling.