Migrate to Next.js 16 and BiomeJS

[google-labs-jules]

This PR updates the project to use Next.js 16 and React 19. It also replaces the ESLint/Prettier stack with BiomeJS for faster and more unified linting and formatting. Code changes include updating page/route handlers to await params (a breaking change in Next.js 15+), fixing TypeScript errors related to React 19 types, and addressing linter findings. A new unit test configuration (vitest.unit.config.ts) was added to facilitate running tests without Docker.

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PR created automatically by Jules for task 6999519153804907158 started by @kellertobias

[google-labs-jules]

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[kellertobias]

This fails the build in the install phase

2025-12-06T03:30:34.0332262Z ##[group]Run npm ci
2025-12-06T03:30:34.0332864Z �[36;1mnpm ci�[0m
2025-12-06T03:30:34.0355435Z shell: /usr/bin/bash -e {0}
2025-12-06T03:30:34.0355997Z ##[endgroup]
2025-12-06T03:30:40.3770629Z npm error code ERESOLVE
2025-12-06T03:30:40.3785801Z npm error ERESOLVE could not resolve
2025-12-06T03:30:40.3786460Z npm error
2025-12-06T03:30:40.3786891Z npm error While resolving: @headlessui/[email protected]
2025-12-06T03:30:40.3787460Z npm error Found: [email protected]
2025-12-06T03:30:40.3787881Z npm error node_modules/react
2025-12-06T03:30:40.3788336Z npm error react@"^19.2.1" from the root project
2025-12-06T03:30:40.3788931Z npm error peer react@">= 16" from @heroicons/[email protected]
2025-12-06T03:30:40.3790133Z npm error node_modules/@heroicons/react
2025-12-06T03:30:40.3790487Z npm error @heroicons/react@"^2.0.18" from the root project
2025-12-06T03:30:40.3790906Z npm error 11 more (@sevenoutman/use-debounced-memo, ...)
2025-12-06T03:30:40.3791224Z npm error
2025-12-06T03:30:40.3791473Z npm error Could not resolve dependency:
2025-12-06T03:30:40.3791954Z npm error peer react@"^16 || ^17 || ^18" from @headlessui/[email protected]
2025-12-06T03:30:40.3792344Z npm error node_modules/@headlessui/react
2025-12-06T03:30:40.3792704Z npm error @headlessui/react@"^1.7.17" from the root project
2025-12-06T03:30:40.3793019Z npm error
2025-12-06T03:30:40.3793276Z npm error Conflicting peer dependency: [email protected]
2025-12-06T03:30:40.3793590Z npm error node_modules/react
2025-12-06T03:30:40.3793952Z npm error peer react@"^16 || ^17 || ^18" from @headlessui/[email protected]
2025-12-06T03:30:40.3794452Z npm error node_modules/@headlessui/react
2025-12-06T03:30:40.3794822Z npm error @headlessui/react@"^1.7.17" from the root project
2025-12-06T03:30:40.3795140Z npm error
2025-12-06T03:30:40.3795442Z npm error Fix the upstream dependency conflict, or retry
2025-12-06T03:30:40.3795829Z npm error this command with --force or --legacy-peer-deps
2025-12-06T03:30:40.3796278Z npm error to accept an incorrect (and potentially broken) dependency resolution.
2025-12-06T03:30:40.3796970Z npm error
2025-12-06T03:30:40.3797165Z npm error
2025-12-06T03:30:40.3797387Z npm error For a full report see:
2025-12-06T03:30:40.3797880Z npm error /home/runner/.npm/_logs/2025-12-06T03_30_36_310Z-eresolve-report.txt
2025-12-06T03:30:40.3798520Z npm error A complete log of this run can be found in: /home/runner/.npm/_logs/2025-12-06T03_30_36_310Z-debug-0.log
2025-12-06T03:30:40.3896038Z ##[error]Process completed with exit code 1.

[google-labs-jules]

This fails the build in the install phase

2025-12-06T03:30:34.0332262Z ##[group]Run npm ci
2025-12-06T03:30:34.0332864Z �[36;1mnpm ci�[0m
2025-12-06T03:30:34.0355435Z shell: /usr/bin/bash -e {0}
2025-12-06T03:30:34.0355997Z ##[endgroup]
2025-12-06T03:30:40.3770629Z npm error code ERESOLVE
2025-12-06T03:30:40.3785801Z npm error ERESOLVE could not resolve
2025-12-06T03:30:40.3786460Z npm error
2025-12-06T03:30:40.3786891Z npm error While resolving: @headlessui/[email protected]
2025-12-06T03:30:40.3787460Z npm error Found: [email protected]
2025-12-06T03:30:40.3787881Z npm error node_modules/react
2025-12-06T03:30:40.3788336Z npm error react@"^19.2.1" from the root project
2025-12-06T03:30:40.3788931Z npm error peer react@">= 16" from @heroicons/[email protected]
2025-12-06T03:30:40.3790133Z npm error node_modules/@heroicons/react
2025-12-06T03:30:40.3790487Z npm error @heroicons/react@"^2.0.18" from the root project
2025-12-06T03:30:40.3790906Z npm error 11 more (@sevenoutman/use-debounced-memo, ...)
2025-12-06T03:30:40.3791224Z npm error
2025-12-06T03:30:40.3791473Z npm error Could not resolve dependency:
2025-12-06T03:30:40.3791954Z npm error peer react@"^16 || ^17 || ^18" from @headlessui/[email protected]
2025-12-06T03:30:40.3792344Z npm error node_modules/@headlessui/react
2025-12-06T03:30:40.3792704Z npm error @headlessui/react@"^1.7.17" from the root project
2025-12-06T03:30:40.3793019Z npm error
2025-12-06T03:30:40.3793276Z npm error Conflicting peer dependency: [email protected]
2025-12-06T03:30:40.3793590Z npm error node_modules/react
2025-12-06T03:30:40.3793952Z npm error peer react@"^16 || ^17 || ^18" from @headlessui/[email protected]
2025-12-06T03:30:40.3794452Z npm error node_modules/@headlessui/react
2025-12-06T03:30:40.3794822Z npm error @headlessui/react@"^1.7.17" from the root project
2025-12-06T03:30:40.3795140Z npm error
2025-12-06T03:30:40.3795442Z npm error Fix the upstream dependency conflict, or retry
2025-12-06T03:30:40.3795829Z npm error this command with --force or --legacy-peer-deps
2025-12-06T03:30:40.3796278Z npm error to accept an incorrect (and potentially broken) dependency resolution.
2025-12-06T03:30:40.3796970Z npm error
2025-12-06T03:30:40.3797165Z npm error
2025-12-06T03:30:40.3797387Z npm error For a full report see:
2025-12-06T03:30:40.3797880Z npm error /home/runner/.npm/_logs/2025-12-06T03_30_36_310Z-eresolve-report.txt
2025-12-06T03:30:40.3798520Z npm error A complete log of this run can be found in: /home/runner/.npm/_logs/2025-12-06T03_30_36_310Z-debug-0.log
2025-12-06T03:30:40.3896038Z ##[error]Process completed with exit code 1.

I have added overrides to package.json to resolve the peer dependency conflicts with npm ci. This forces the usage of React 19 even for packages that haven't updated their peer dependency ranges yet.