ESLint lints the web client's build output: the tsup runner bundle isn't ignored, so the only lint warning comes from vendored undici #2043

The problem

clients/web/eslint.config.js ignores dist, storybook-static and coverage — but not build:

globalIgnores(["dist", "storybook-static", "coverage"]),

clients/web/build/ is the tsup runner bundle (the prod Node web server, ~1.2 MB of generated JS including a vendored undici). Because it isn't ignored, npm run lint in clients/web lints generated third-party code, and the only lint output the web client produces today comes from inside that bundle:

clients/web/build/undici-HXPKCIY3.js
  16021:11  warning  Unused eslint-disable directive (no problems were reported from 'no-fallthrough')

✖ 1 problem (0 errors, 1 warning)

That directive is undici's own, in undici's own source. There is nothing to fix in this repo, and nothing anyone can act on.

Why web is the odd one out

The other three clients already ignore their build output. Web is the only client that emits both dist (the Vite SPA) and build (the tsup runner), and it looks like only the first was carried into the ignore list:

The root config is consistent with the three: it already ignores core/**/build/**, core/**/dist/** and test-servers/build/**.

Why it's worth fixing rather than tolerating

It's a warning today, so validate still passes — but:

• It trains people to ignore lint output. The web client's lint is never clean, and the one line it prints is noise. A real warning added later lands in a channel everyone has learned to skim past.
• A rule promotion turns generated code into a gate failure. reportUnusedDisableDirectives is a warning by default; anything that raises it — or any new rule that a bundled dependency happens to trip — fails validate on a file nobody wrote. Enable @typescript-eslint/no-floating-promises so an unhandled rejection can't fail the gate again #1959 (enabling no-floating-promises across all five scopes) is exactly the kind of change that walks into this.
• It's wasted work. Every npm run lint parses ~1.2 MB of bundled output, on a path that is gitignored and rebuilt on every npm run build.
• Nothing guards it. verify:format-coverage and verify:typecheck-coverage assert that first-party source is covered; there is no guard asserting that generated output is excluded, so this drifted silently and would again.

The fix

Add build to the web client's ignore list, matching its three siblings:

-  globalIgnores(["dist", "storybook-static", "coverage"]),
+  globalIgnores(["build", "dist", "storybook-static", "coverage"]),

Verified locally: with that one line, npx eslint . in clients/web prints nothing and exits 0; without it, it prints the undici warning above.

While in there, it's worth a quick check of whether the same omission exists anywhere else a bundler writes into a linted scope.

Acceptance

• cd clients/web && npm run lint produces no output and exits 0 on a tree that has been built.
• npm run validate from the root stays green.
• No file under any clients/*/build or clients/*/dist is reported by ESLint from any scope.

Notes

Found while smoke-testing the v2.3.0 milestone. Pre-existing — not a regression introduced by anything in this milestone.