chore: drop the orphaned root override, and correct the TUI coverage note

Review follow-ups on #1983 (Copilot's suppressed comments).

Removing `ink-form` from the root dependencies left `overrides.ink-select-input`
with nothing to override: no root dependency reaches that package any more, and
the regenerated lock carries no entry for it. The override that matters lives in
`clients/tui/package.json`, where the build resolves `ink-form` — and it is what
puts `ink-select-input@6` (rather than the React-18-era v5) into the bundle.

The README paragraph above the new bundling section still described the Ink
components and `App.tsx` as an interim coverage exclusion. #1501 lifted that:
`vitest.config.ts` now gates all of `src/**`, excluding only the pure
`src/tui-servers.ts` re-export. Corrected to match the config it describes.

Closes #1952

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WLYmVPVLdeYpE6aMTUsCks

package.json

@@ -99,9 +99,6 @@
     "yaml": "^2.9.0",
     "zod": "^4.4.3"
   },
-  "overrides": {
-    "ink-select-input": "^6.2.0"
-  },
   "engines": {
     "node": ">=22.19.0"
   },