refactor(DT-3906): Add knip

[tegan-temporal]

Description & motivation 💭

Before starting the larger work of migrating Svelte 4 syntax to Svelte 5, I wanted to add and configure Knip to help monitor dead code and unused dependancies. As you can see from the PR we have a number of unused dependencies.

In the future we might want to add Knip to the dangerfile or CI so we can ensure dead code is cleaned up as we go.

Screenshots (if applicable) 📸

❯ pnpm knip

> @temporalio/ui@2.49.1 knip /Users/tegan/Projects/ui
> knip

Unused dependencies (1)
lodash.groupby             package.json:113:6
Unused devDependencies (30)
@babel/preset-typescript          package.json:127:6
@grpc/grpc-js                     package.json:130:6
@storybook/addon-docs             package.json:134:6
@storybook/blocks                 package.json:140:6
@storybook/icons                  package.json:141:6
@temporalio/testing               package.json:154:6
@types/base-64                    package.json:157:6
@types/mkdirp                     package.json:161:6
@types/sanitize-html              package.json:163:6
@types/unist                      package.json:165:6
@typescript-eslint/eslint-plugin  package.json:167:6
@typescript-eslint/parser         package.json:168:6
c8                                package.json:172:6
chalk                             package.json:173:6
ejs                               package.json:177:6
esbuild                           package.json:178:6
google-protobuf                   package.json:190:6
mock-socket                       package.json:198:6
npm-run-all                       package.json:201:6
postcss-cli                       package.json:204:6
postcss-import                    package.json:206:6
react-dom                         package.json:212:6
rehype-document                   package.json:213:6
rehype-format                     package.json:214:6
rehype-stringify                  package.json:215:6
svelte-eslint-parser              package.json:227:6
svelte-highlight                  package.json:228:6
svelte-loader                     package.json:229:6
tslib                             package.json:234:6
webpack                           package.json:242:6
Unlisted dependencies (1)
@vitest/coverage-v8  vitest.config.ts
Unresolved imports (2)
../../src/theme/colors  scripts/audit-tailwind-colors/utilities.ts:4:20         
../../types/global      src/lib/utilities/write-actions-are-allowed.test.ts:6:31

Design Considerations 🎨

Testing 🧪

How was this tested 👻

• Manual testing
• E2E tests added
• Unit tests added

Steps for others to test: 🚶🏽‍♂️🚶🏽‍♀️

Checklists

Draft Checklist

Merge Checklist

Issue(s)

DT-3906

Docs

Any docs updates needed?

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Project	Deployment	Actions	Updated (UTC)
holocene	Ready	Preview, Comment	Apr 28, 2026 10:12pm

[rossnelson]

No harm in adding this, thanks! Looks like it has nice config for ignores as well in case things get too noisy in the future.