[scottzx]

Problem and fix

Fresh frontend CI installs fail with Yarn YN0028 because the committed chat-ui workspace is missing from the lockfile. Once installation succeeds, the existing chat-ui sources fail the repository lint rules.

Register the existing workspace/dependencies in the lockfile, declare its already-used esbuild build dependency, and apply the existing repository formatting. Replace broad types with unknown or existing model types, remove unused bindings, and explain intentional parse/highlight fallbacks. Configure only the package build script for its existing ES module syntax, using the Node ESLint plugin's module configuration.

Add four compatibility tests and run them in frontend CI. Runtime behavior is preserved, including dynamic tool payloads, malformed JSON fallbacks, explicit file locations, and historical-turn change reports.

Validation

• yarn install --immutable: passed.
• yarn check: passed with zero lint errors or warnings.
• yarn test:chat-ui: 4 passed.
• yarn build: production Webpack + gulp passed; 5 existing build warnings.
• chat-ui standalone typecheck and ESM/CJS/declaration builds: passed.
• Independent review and source/runtime AST comparison: no findings.

Scope

Built from clean main at 68c5054. Only chat-ui, its dependency/configuration records, and frontend CI/test wiring are included. No ACP Workbench, task hierarchy, submodule updates, or uncommitted shared-workspace changes are included. This separately unblocks the Feature Blueprint retirement in #415.