chore: widen verify:dep-lockstep to declared cross-install copies (#2226)

`clients/cli` resolved `@types/node` 24.13.1 against the root's 24.13.3.
Neither client declares it — #2196 consolidated it to the root — so the cli
copy arrived transitively via `@types/express` and was constrained by no
range of ours. `verify:dep-lockstep` reported OK and was right to: it
compares only packages that reach one `tsc` **program** from two installs,
and no one program sees both copies.

Fixes the instance and the class, which the issue notes are not exclusive.

**The class.** The guard grows a second tier alongside the program-derived
one, asking the weaker but broader question `AGENTS.md`'s "one version per
install-crossing dependency" rule actually states: does a package this repo
declares anywhere resolve to two versions across our installs at all? The
candidate set is every name in any install's `dependencies`/`devDependencies`
that more than one install holds a **top-level** copy of — 17 packages today.
Nested copies are excluded: one exists because some dependency asked for a
different version, so it is that dependency's range, not ours.

Neither tier subsumes the other. The program tier sees a copy no manifest
names (the `@modelcontextprotocol/sdk` case, arriving through another
package's `.d.ts`). The declared tier sees a transitive copy no program
loads (this issue), two *clients* disagreeing with no root copy involved
(`@types/react`, web against tui), and the peer shadows `AGENTS.md` calls out
as ungated — `eslint`, `typescript`, `vitest`.

Deny-by-default, with its own empty `TOLERATED_DECLARED_SKEW` and the same
within-a-major rule, now stated once in a shared `toleratesSkew` so the two
tiers cannot drift.

**The instance, and three others the new tier surfaced.** All four were
patch-level:

- `@types/node` — cli 24.13.1 vs root 24.13.3. Transitive, so it takes an
  `overrides` entry in `clients/cli` (the repo's sanctioned lever for a
  transitive pin), at the root's own `^24.12.4` rather than a frozen number.
- `@types/react` — web 19.2.18 vs tui 19.2.17.
- `react` — web 19.2.8 vs root/tui 19.2.7.
- `@vitejs/plugin-react` — web 6.0.5 vs root 6.0.2.

The last three are `npm update` in the stale install: it moves the lockfile
within the declared range without widening a range, which matters for the
root `react ^19.0.0` that `ink`'s externalized-bundle exemption depends on.
No declaration or range changed.

Tests: 4 end-to-end cases (the fixture gains manifest deps and a client-side
`solo` install, so the skew is real and no program holds both copies) and 13
helper cases.

Closes #2226

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J86a6vMcA9csPtdsg7ZcCZ
Signed-off-by: cliffhall <cliff@futurescale.com>

package-lock.json

@@ -1596,12 +1596,12 @@
       }
     },
     "node_modules/@vitejs/plugin-react": {
-      "version": "6.0.2",
-      "resolved": "https://registry.npmjs.org/@vitejs/plugin-react/-/plugin-react-6.0.2.tgz",
-      "integrity": "sha512-DlSMqo4WhThw4vB8Mpn0Woe9J+Jfq1geJ61AKW0QEgLzGMNwtIMdxbDUzLxcun8W7NbJO0e2Jg/Nxm3cCSVzzg==",
+      "version": "6.1.1",
+      "resolved": "https://registry.npmjs.org/@vitejs/plugin-react/-/plugin-react-6.1.1.tgz",
+      "integrity": "sha512-yxLaQV9gkhS8ezJqCM6+ndU7mDY6gqAg75NQ+0IjwEI8IYOmQCgkRwHKVSfWXW076DsqMo0Dk+0FK1U+M5RgFw==",
       "license": "MIT",
       "dependencies": {
-        "@rolldown/pluginutils": "^1.0.0"
+        "@rolldown/pluginutils": "^1.0.1"
       },
       "engines": {
         "node": "^20.19.0 || >=22.12.0"
@@ -1609,6 +1609,7 @@
       "peerDependencies": {
         "@rolldown/plugin-babel": "^0.1.7 || ^0.2.0",
         "babel-plugin-react-compiler": "^1.0.0",
+        "oxc-transform-react": "^0.145.0",
         "vite": "^8.0.0"
       },
       "peerDependenciesMeta": {
@@ -1617,6 +1618,9 @@
         },
         "babel-plugin-react-compiler": {
           "optional": true
+        },
+        "oxc-transform-react": {
+          "optional": true
         }
       }
     },
@@ -4429,9 +4433,9 @@
       }
     },
     "node_modules/react": {
-      "version": "19.2.7",
-      "resolved": "https://registry.npmjs.org/react/-/react-19.2.7.tgz",
-      "integrity": "sha512-HNe9WslTbXmFK8o8cmwgAeJFSBvt1bPdHCVKtaaV+WlAN36mpT4hcRpwbf3fY56ar2oIXzsBpOAiIRHAdY0OlQ==",
+      "version": "19.2.8",
+      "resolved": "https://registry.npmjs.org/react/-/react-19.2.8.tgz",
+      "integrity": "sha512-PWaYA1L/q9u2u7xYQi+Y3L3Yfnie7XyLeaJICV1MGD6LprsBxcAqGjYyr0eY3p+QdsA+x/Irkt4Qif8D63+Sbw==",
       "license": "MIT",
       "engines": {
         "node": ">=0.10.0"