feat(website): predefined COVID variant signatures from collections (W-ASAP)

[fhennig]

resolves #1199

Adds support for predefined variant signatures in the W-ASAP Variant Explorer mode, as an alternative to computing signatures from clinical sequences. For COVID, these come from a configured collections source (filtered by user ID, organism, and a tag in the description).

Summary

• Adds a predefinedVariantsSource config to WasapPageConfig specifying where to fetch predefined variant collections from (userId, tag, label); the organism is taken from the new internalName field on the base config
• Pre-fetches matching collections via getCollectionSummaries and exposes them in a downshift autocomplete combobox in the filter panel
• Extends WasapVariantFilter with a signatureType field ('computed' | 'predefined') and predefined-specific fields (collectionId, newMutationsOnly); serialised to/from URL
• signatureType defaults to 'computed' and is omitted from the URL for backwards compatibility with existing bookmarks
• Refactors the variant filter type from a discriminated union to a flat type (consistent with WasapUntrackedFilter), removing the need to pass computedDefaults through the component tree
• Extracts SignatureType to wasapPageConfig.ts alongside all other WASAP types
• Adds internalName to WasapPageConfigBase so the organism key is accessible from the config directly
• Updates the Variant Explorer info box to describe both predefined and computed signature modes

Screenshot

Testing

• WasapPageStateHandler.spec.ts — URL round-trip tests for the predefined signatureType: serialising a WasapVariantFilter with signatureType: 'predefined', collectionId, and newMutationsOnly into URL params and parsing them back produces the original state.
• CollectionCombobox.browser.spec.tsx (new file) — Browser tests for the autocomplete combobox used to pick a predefined collection: selecting a collection from the dropdown, clearing the selection via the clear button, and blur behaviour (committing a valid value on blur, rejecting an invalid one with an error state).
• VariantExplorerFilter.browser.spec.tsx — Browser tests for the predefined path in the filter panel: switching the "Variant definition source" dropdown from computed → predefined, selecting a collection, and toggling the "Mutation not in parent" checkbox.

PR Checklist

• All necessary documentation has been adapted.
• The implemented feature is covered by an appropriate test.

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Project	Deployment	Actions	Updated (UTC)
dashboards	Ready	Preview, Comment	Jun 8, 2026 8:36am

[Copilot]

Pull request overview

Adds support in the W-ASAP “Variant Explorer” for selecting curated, predefined COVID variant mutation signatures from Collections (in addition to the existing computed-from-clinical-signatures flow), including URL serialization and UI updates.

Changes:

• Extends WASAP config/types and URL state handling to support signatureType: 'computed' | 'predefined' plus predefined-only params (collectionId, newMutationsOnly).
• Adds a Downshift-based CollectionCombobox and updates the Variant Explorer filter panel to switch between computed vs predefined signature sources.
• Fetches predefined collections from the backend (by user + organism) and adds tests for URL round-tripping and the new filter UI.

Reviewed changes

Copilot reviewed 15 out of 16 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
website/src/views/pageStateHandlers/WasapPageStateHandler.ts	Parse/serialize new predefined variant params into/from the URL.
website/src/views/pageStateHandlers/WasapPageStateHandler.spec.ts	Adds URL round-trip tests for predefined signature params.
website/src/types/wastewaterConfig.ts	Adds internalName and configures predefined variants source for COVID.
website/src/components/views/wasap/wasapPageConfig.ts	Adds internalName, SignatureType, and extends WasapVariantFilter.
website/src/components/views/wasap/WasapPage.tsx	Logs query errors; hides clinical fetch info for predefined signatures.
website/src/components/views/wasap/useWasapPageData.ts	Adds predefined-signature fetching via backend collections.
website/src/components/views/wasap/initialMeanProportionInterval.spec.ts	Updates test fixtures to include signatureType.
website/src/components/pageStateSelectors/wasap/WasapPageStateSelector.tsx	Prefetches matching collections and passes results/label into the variant filter.
website/src/components/pageStateSelectors/wasap/utils/CollectionCombobox.tsx	New Downshift combobox for selecting a predefined collection.
website/src/components/pageStateSelectors/wasap/utils/CollectionCombobox.browser.spec.tsx	Browser tests for combobox selection/clearing/blur behavior.
website/src/components/pageStateSelectors/wasap/InfoBlocks.tsx	Updates info text to describe both signature modes.
website/src/components/pageStateSelectors/wasap/filters/VariantExplorerFilter.tsx	UI to toggle computed vs predefined and pick a collection / new-mutations-only.
website/src/components/pageStateSelectors/wasap/filters/VariantExplorerFilter.browser.spec.tsx	Browser tests covering the predefined path in the filter panel.
website/src/backendApi/backendService.ts	Extends getCollectionSummaries to accept an optional userId filter.
website/package.json	Adds downshift dependency.
website/package-lock.json	Locks downshift and updates dependency metadata.

Files not reviewed (1)

• website/package-lock.json: Language not supported

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[fengelniederhammer]

LGTM (not sure why the diff shows 31 commits now, looks like something went wrong during the rebase)