fix(lint): exclude consumer fixtures from the root tsc program

[acebytes]

The regression

npm run lint (root tsc --noEmit --project tsconfig.json) exits 2 on main with:

packages/plugin-types/fixtures/globals/jsc-with-globals/main.ts(59,1): error TS2578: Unused '@ts-expect-error' directive.
packages/plugin-types/fixtures/globals/jsc-with-globals/main.ts(64,1): error TS2578: Unused '@ts-expect-error' directive.
packages/plugin-types/fixtures/globals/jsc-with-globals/main.ts(67,1): error TS2578: Unused '@ts-expect-error' directive.

Introduced by #8 (feat/url-globals-subpath), which added the fn-182 globals consumer fixtures under packages/plugin-types/fixtures/globals/.

Root cause

The root tsconfig.json has no include, so the lint program sweeps every .ts file under the repo root that isn't excluded — including the consumer fixtures. Under the root config the compile runs with the default lib (which includes lib.dom, so URL is fully typed). The jsc-with-globals fixture's deliberate @ts-expect-error lines therefore no longer suppress a real error, and tsc reports TS2578 for each.

The fixtures are designed to compile only under their own per-fixture tsconfigs ("lib": ["ES2020"], "types": []), driven by the consumer-fixture harness packages/plugin-types/fixtures/globals/run.mjs. Sweeping them in any other program is a category error — the whole point of the fixtures is to typecheck against a specific, minimal lib environment.

The fix

Exclude fixtures from the root program:

-  "exclude": ["node_modules", "dist", "docs-site"]
+  "exclude": ["node_modules", "dist", "docs-site", "packages/*/fixtures"]

This deliberately does not touch the fixtures or their per-fixture tsconfigs — the @ts-expect-error lines are the fn-182 contract test and must keep erroring under their tsconfigs. That contract is still enforced by npm test → node fixtures/globals/run.mjs, which runs all 4 fixture cases with exact pass/fail expectations (and TS2578 would fail the jsc-with-globals case if a directive ever became unused there).

Verification (on this branch)

Check	Result
npm run lint	exit 0
npm run build	exit 0
npm test	exit 0 — 59/59 workspace tests; globals harness: all 4 fixture cases PASS (jsc-with-globals, jsc-types-array, jsc-without-globals fails-with-only-TS2304 as required, webview-dom)
npm run validate-schema	exit 0 (community-plugins skip is pre-existing/environmental)
tsc --listFilesOnly sweep diff	0 fixture files in the root program; all 55 package src/ + __tests__ files still swept

Note: CI has no lint job

This regression shipped because the only workflow (docs.yml) runs docs checks — nothing in CI runs npm run lint. Suggested follow-up (not in this PR): add a small CI job running npm run lint && npm test on PRs so root-program regressions like this are caught at review time.