feat(website): Metadata documentation for generated fields

[tombch]

This PR does the following:

• Adds definitions for common metadata fields in ‎kubernetes/loculus/templates/_common-metadata.tpl.
• Adds the basic files/config for navigating to and viewing metadata documentation in Loculus (without needing e.g. a Pathoplexus overlay).
• Updates the documentation structure with tabs for input and generated fields, ability to link to a specific field on the page in the URL, and a search bar.

resolves #

Screenshot

PR Checklist

• All necessary documentation has been adapted.
• The implemented feature is covered by appropriate, automated tests.
• Any manual testing that has been done is documented (i.e. what exactly was tested?)

🚀 Preview: https://generated-field-docs.loculus.org

[claude]

Claude finished @tombch's task in 3m 4s —— View job

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Code Review

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Good addition overall — the tab structure, search bar, and URL-addressable field links are all solid UX improvements. A few issues worth addressing before merge:

Bug (inline comment on line 61): fieldLinkId.split('-')[1] breaks for any field name that contains a hyphen (e.g. Nextclade fields like coverage-main). The header and field name are joined with - but not escaped, so split('-') produces more than two parts. Use indexOf('-') to split only on the first occurrence.

SSR safety (inline comment on line 45): Reading window.location.search in the lazy useState initializer will throw on the server during Astro SSR if this component is ever rendered with client:load or client:idle. The OrganismMetadataTableSelector already handles this correctly by reading window.location inside useEffect — recommend the same pattern here.

Performance (inline comments on lines 53 and 134–138):

• inputFieldNames is a new Set(...) recreated on every render; wrap in useMemo([organism]).
• inputFieldTypes is rebuilt inside each iteration of the header-groups .map(), so it runs N times (once per group). Move it outside the loop.

Minor (inline comment on config.ts line 71): The InputField.definition comment ("for submitters") is now slightly misleading since definition has been added to Metadata too.

No tests — the checklist item is unchecked, which is fine for a docs/UI feature, but worth noting that the hash-parsing logic in particular would benefit from a unit test given the edge cases.

[anna-parker]

Already looks great here and on the PPX as well - it might be good to already add the descriptions for the INSDC fields here as well

[anna-parker]

I guess as this will now lead all instances running loculus to have a docs link with Fill this in with documentation for your loculus instance. maybe we dont want to add a link to the docs by default to the top? @theosanderson do you have thoughts?

[anna-parker]

not a react expert but my understanding is we added popstate to get ensure that the state of the page and the URL are kept in sync when a user would navigate forwards and backwards, could this now get out of sync?