Upgrade to Elm Pages 3 and update depends

[katjam]

Description

Upgrade out framework & dependencies

Acceptance Criteria

• [ ] elm pages is version 3.0.x
• [ ] node is version 20
• [ ] node scripts run without error (postinstall, start, build, format, test)
• [ ] https://github.com/GenderedIntelligence/the-trans-dimension/issues/404
• [ ] site builds and deploys without error
• [ ] pages are identical to release on https://transdimension.uk

Plan first

• [x] Upgrade other deps
• [x] Upgrade to elm-pages v3
• [x] move source files
• [x] move theme and route files out to get index working in v3
• [x] replace Path with UrlPath
• [x] replace Cmd with Effect
• [x] amend script/src/AddRoute.elm & AddStaticRoute to use elm-css
• [x] Amend default mainfest in app/Api.elm ? This is new here in v3 - check where was before

Considerations

• migrate Decoders
• migrate DataSource
• amend Route exports for data and ActionData

Initial port of Theme & Routes

• [x] About
• [ ] 404
• [ ] Events (index & single)
• [x] Partners index
• [x] Partner single
• [ ] Index
• [ ] JoinUs
• [x] News index
• [x] News item
• [ ] Add Paginator to News Item (Theme.Paginator has own Msg type) - are we using this?
• [ ] Add Events back into Partner_.elm pages
• [x] Privacy
• [x] Meta / Head
• [ ] #432

Next

• [ ] Clear out with elm-review
• [ ] Review efficiency of build and data loading in context of below list
• [ ] Update readme (see notes below)

Review issues after upgrade

Some of them might be able move to AC

• [ ] https://github.com/GenderedIntelligence/the-trans-dimension/issues/391
• [ ] https://github.com/GenderedIntelligence/the-trans-dimension/issues/386
• [ ] https://github.com/GenderedIntelligence/the-trans-dimension/issues/364
• [ ] https://github.com/GenderedIntelligence/the-trans-dimension/issues/351
• [ ] https://github.com/GenderedIntelligence/the-trans-dimension/issues/348
• [ ] https://github.com/GenderedIntelligence/the-trans-dimension/issues/296
• [ ] https://github.com/GenderedIntelligence/the-trans-dimension/issues/269
• [ ] https://github.com/GenderedIntelligence/the-trans-dimension/issues/268
• [ ] https://github.com/GenderedIntelligence/the-trans-dimension/issues/210
• [ ] https://github.com/GenderedIntelligence/the-trans-dimension/issues/72
• [ ] https://github.com/GenderedIntelligence/the-trans-dimension/issues/17

Readme

• [ ] Update any refs and links to elm-pages v3
• [ ] structure of code updated e.g. app/ is for files specific to elm-pages our custom additional modules in src/

[katjam]

Suggested upgrade path for v2 to v3: https://discourse.elm-lang.org/t/introducing-elm-pages-v3-full-stack-elm-and-scripts/9185/12

elm-pages v3 docs: https://elm-pages.com/docs/

[katjam]

removing OptimizedDecoder's and replacing with plain Decoders, and using the new BackendTask and FatalError APIs instead of DataSource

https://github.com/dillonkearns/elm-pages-v3-beta/blob/master/docs/3.0-upgrade-notes.md

[kimadactyl]

ahha i didnt see this ticket! now have a really good idea what this is taking to get done, wow its a lot!