Add a DANDI Atlas entry to the Open with menu

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What

Adds a "DANDI Atlas" entry to the "Open with" menu on the Dandiset landing page, linking to https://atlas.dandiarchive.org/?atlas=<key>#dandiset=<id>. The entry only appears for Dandisets that the atlas viewer can actually display.

Closes #2870.

Why the entry is gated

An identifier the viewer does not know about is not an error there: applyURLState gates on dandisetToStructures[did], so the deep link silently drops the user on the atlas overview with no explanation. Showing the entry unconditionally would produce a dead-end link on most Dandisets, so it is better to show it only when the destination will work.

dandi/dandi-atlas#27 added a dandisets field to each atlas record in data/atlases_index.json for exactly this. That file is 2.9 KB and is served with access-control-allow-origin: *, so the client can fetch it directly.

How

web/src/utils/atlas.ts fetches the index once per session and inverts it into a Map from Dandiset identifier to atlas. The component looks up the current identifier and renders the entry only on a hit. The shape follows utils/doi.ts: bare axios against a full URL, and a catch that logs and fails safe rather than throwing, since the rest of the page does not depend on this link. A failed request clears the cache so a later navigation retries.

Two details worth calling out:

A Dandiset can belong to more than one atlas. For example 000947 is registered against both D99 and NMT. #2870 says linking to one of them is fine, so the first match in index order wins. This is deterministic but arbitrary; if a preferred atlas per Dandiset is wanted later, that belongs in the index rather than here.

The entry is restricted to production. The viewer only indexes production Dandisets, and identifiers collide across deployments: sandbox 000017 is unrelated data from the 000017 in the Allen CCF list, so linking it would send the user to the wrong dataset. The check is metadata.url starting with https://dandiarchive.org/, matching how the adjacent Neurosift URL already detects the instance. Using metadata.url rather than window.location.origin means a locally served client pointed at the production API still gets the link, which is what makes the verification below possible.

Verification

Ran the dev client against the production API and drove it with Playwright:

Dandiset	Expected	Result
000022 (Allen CCF)	entry shown	?atlas=allen_ccf#dandiset=000022
000947 (D99 + NMT)	entry shown, first match	?atlas=d99#dandiset=000947
000004 (no atlas)	entry absent	absent, Neurosift still present

000022 reproduces the example URL from #2870 exactly. Loading that URL in the viewer resolves correctly: it selects Allen CCF, opens the "Dandiset 000022" panel with 26 subjects and 56 brain regions, and highlights the relevant regions.

Then restarted against the sandbox API and loaded sandbox 000017, whose identifier is in the Allen CCF list. The entry is correctly absent while Neurosift still renders, confirming the instance gate.

npm run lint and npm run type-check both pass.

Note for reviewers: the deploy preview cannot show this

netlify.toml builds deploy previews against the sandbox API (context.deploy-preview.environment), and the entry is restricted to production for the reason above, so it is correctly absent everywhere on the preview link. I confirmed this on the preview itself: sandbox 000017 shows Neurosift but no atlas entry. That is the intended behavior, not a broken build. To see the entry, run the client locally with VITE_APP_DANDI_API_ROOT=https://api.dandiarchive.org/api/ and open 000022.

On tests

I did not add an e2e test. The suite runs against a local deployment, where the production gate correctly suppresses the entry, so the positive case cannot be exercised without stubbing the Dandiset info response to claim a production metadata.url. A test that only asserts the entry is absent would pass just as well if the feature were entirely broken, which seemed worse than no test. Happy to add the stubbed version if you would rather have the coverage.

🤖 Generated with Claude Code

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