feat: upgrade to React Router v8

[SimeonGriggs]

Closes #141

Summary

Coordinated React Router v8 upgrade after the production outage from Dependabot's partial bump (#138 / fixed in #140).

Dependency bumps

Package	From	To
react-router	^7.17.0	^8.3.0
@react-router/dev	^7.17.0	^8.3.0
@react-router/fs-routes	^7.17.0	^8.3.0
vite	^6.4.3	^7.3.6
@cloudflare/vite-plugin	^1.40.0	^1.50.0
wrangler	^4.98.0	^4.118.0
@cloudflare/workers-types	^4…	^5…
vitest	^3.2.6	^4.1.10 (Vite 7 peer)
engines.node	>=22	>=22.22

App changes required by v8 middleware

• Added typed cloudflareContext via createContext (app/context.ts)
• workers/app.ts now returns a RouterContextProvider instead of a plain object (this was the production crash)
• OG loaders read context.get(cloudflareContext) instead of context.cloudflare
• Removed AppLoadContext usage from entry.server.tsx
• Removed graduated future.v8_viteEnvironmentApi; set top-level splitRouteModules: true
• Normalized .data path suffixes in redirect helper for pass-through request URLs

Verification

• pnpm run build ✅
• pnpm test — 18/18 ✅
• Local wrangler dev: /, /api, /palette/... return 200
• pnpm typecheck still has pre-existing catalyst / Sanity errors (unchanged from main)

Please check the Workers preview build

Opening this PR should trigger a Cloudflare Workers preview build — please confirm that preview URL loads before merging.

  

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Status	Name	Latest Commit	Preview URL	Updated (UTC)
✅ Deployment successful! View logs	tints-dev	75c0efa	Commit Preview URL Branch Preview URL	Aug 03 2026, 11:28 AM