fix(tui): widen the root react range so an external ink can't split React

Review follow-up on #1983. Copilot was right, and about a hazard this repo
had already proven and then documented away: the claim that ink's ">=19"
peer "keeps npm from hoisting it next to a React the Inspector couldn't
also use" is false. A consumer pinning React 19.0 satisfies ">=19" while
`^19.2.4` nests underneath, so ink renders through their React and the
bundle through ours — the #1952 crash, one level up, breaking TUI startup
rather than just its forms.

Bundling ink closes it (verified: with a `createRequire` banner for the
inlined CJS, since react-reconciler calls `require("react")` and
signal-exit@3 `require("assert")`), but costs ~1.4MB — react-reconciler
and yoga-layout come along. The root `react` range closes it for free
instead: `^19.0.0` is open to the whole major, so npm can satisfy our
React and a consumer's pinned React 19 with one copy, and an external ink
resolves the same copy the bundle does.

Verified against both consumer trees — the reporter's (React 18 + ink 5)
and a pinned React 19.0.0 + ink 6.8.0, which splits under `^19.2.4`.

That makes the range load-bearing while looking like an ordinary version
bump, so the tests pin it: the root range must equal ink's own declared
peer floor. They also assert each exempt package is both external and a
root dependency — external means consumers install it, the mirror image
of the inlined ones, which must not be root-declared.

The docs in all four places now say ink is exempt on cost and never on a
peer range, and name that claim as one we got wrong.

Closes #1952

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

package-lock.json

@@ -26,7 +26,7 @@
         "ink": "^6.0.0",
         "open": "^10.2.0",
         "pino": "^9.14.0",
-        "react": "^19.2.4",
+        "react": "^19.0.0",
         "undici": "^8.5.0",
         "vite": "^8.1.5",
         "yaml": "^2.9.0",
@@ -1819,13 +1819,14 @@
       }
     },
     "node_modules/es-toolkit": {
-      "version": "1.47.0",
-      "resolved": "https://registry.npmjs.org/es-toolkit/-/es-toolkit-1.47.0.tgz",
-      "integrity": "sha512-n1GuoD0WEQZMBk5tttoZSqwgyLx01oqa5XsBmCHwPyNe1S9jPBEmtR2pSgp2kJuWE3ciFZ6yRHmY4pM4C3OOkw==",
+      "version": "1.50.0",
+      "resolved": "https://registry.npmjs.org/es-toolkit/-/es-toolkit-1.50.0.tgz",
+      "integrity": "sha512-OyZKhUVvEep9ITEiwHn8GKnMRQIVqoSIX7WnRbkWgJkllCujilqP2rD0u979tkl8wqyc8ICwlc1UBVv/Sl1G6w==",
       "license": "MIT",
       "workspaces": [
         "docs",
-        "benchmarks"
+        "benchmarks",
+        "tests/types"
       ]
     },
     "node_modules/escape-html": {
@@ -3887,9 +3888,9 @@
       }
     },
     "node_modules/string-width": {
-      "version": "8.2.1",
-      "resolved": "https://registry.npmjs.org/string-width/-/string-width-8.2.1.tgz",
-      "integrity": "sha512-IIaP0g3iy9Cyy18w3M9YcaDudujEAVHKt3a3QJg1+sr/oX96TbaGUubG0hJyCjCBThFH+tFpcIyoUHUn1ogaLA==",
+      "version": "8.2.2",
+      "resolved": "https://registry.npmjs.org/string-width/-/string-width-8.2.2.tgz",
+      "integrity": "sha512-GaPUh5gfdrYzqeVNZvUfT23vYYxXzKYidUcnMtJg/3rxRV63EFZy3k6xfKlmfeJD0176lnUV/Usr3XcwSvFzpg==",
       "license": "MIT",
       "dependencies": {
         "get-east-asian-width": "^1.5.0",
@@ -4024,9 +4025,9 @@
       }
     },
     "node_modules/type-fest": {
-      "version": "5.7.0",
-      "resolved": "https://registry.npmjs.org/type-fest/-/type-fest-5.7.0.tgz",
-      "integrity": "sha512-1URUxUqfHFM1c+zfSPsa3gnkO7Aq21qyH75SIduNYz4SzY964rn1X2vCMQaHSHhktiw+0kPa2iyb6PUpXqB6Vg==",
+      "version": "5.8.0",
+      "resolved": "https://registry.npmjs.org/type-fest/-/type-fest-5.8.0.tgz",
+      "integrity": "sha512-YGYEVz3Fm5iy/AybuA0oyNFq7H4CgQNfRp/qfe8nurE1kuCeNm3/vfm9X4Mtl+qLyaKJUh5xrFZwogr41SMjYA==",
       "license": "(MIT OR CC0-1.0)",
       "dependencies": {
         "tagged-tag": "^1.0.0"
@@ -4291,9 +4292,9 @@
       "license": "ISC"
     },
     "node_modules/ws": {
-      "version": "8.21.0",
-      "resolved": "https://registry.npmjs.org/ws/-/ws-8.21.0.tgz",
-      "integrity": "sha512-Vsp28b7DRcimFQvrqu2Wek3z1iYxDCWqHYB8Qsnk/S4RfaCQzPGPyBNuVjJV3cd6UiKtUtp6sNM77gWvzcCH+g==",
+      "version": "8.21.3",
+      "resolved": "https://registry.npmjs.org/ws/-/ws-8.21.3.tgz",
+      "integrity": "sha512-201TZ/kPWxoPr/OKWjquZR1SWKXcvxdH+e1xrx89b3YbmzLMFCLfnaG1HFIgWzJOEWZ7MvpK++odZufgYR50Rw==",
       "license": "MIT",
       "engines": {
         "node": ">=10.0.0"