Enforce shared, client, and server plugin SDK boundaries (#4347)

* fix(plugins): keep React out of the server plugin host

* fix(plugins): align SDK guidance and tests with runtime boundaries

* fix(plugin): loosen the react peer to ~19.1.0

The plugin SDK pins its react peer to exactly 19.1.0, and that pin is
what a downstream `npm i -g @getpaseo/cli` resolves against. So every
user ends up with react 19.1.0 in their global node_modules, where
corporate dependency scanners flag it: the CVE-2025-55182 advisory range
covers 19.1.0 even though the vulnerability itself lives in
react-server-dom-webpack/-parcel/-turbopack, none of which the CLI
installs. The user is then left hand-patching node_modules or
uninstalling Paseo.

Widening the peer to ~19.1.0 lets a downstream install pick the latest
19.1.x patch (19.1.9 today) while this repo stays on 19.1.0, which the
root override still pins.

Keeping the repo itself on 19.1.0 is deliberate. react-native 0.81.5
embeds a 19.1.0 Paper renderer that hard-throws "Incompatible React
versions" on any exact mismatch, and it is reachable from Fabric builds
too: RendererImplementation.js requires the Paper shim unconditionally
in findNodeHandle, unstable_batchedUpdates, sendAccessibilityEvent and
three other entry points, and react-native-gesture-handler re-exports
findNodeHandle. Bumping the app's react is therefore not safe until
react-native moves.

The published CLI tree contains no react-native, so downstream installs
are not subject to that constraint.

Supersedes the earlier 19.1.5/19.1.9 version-bump approach on this
branch, which would have broken the mobile app.

* Enforce example import ownership including client types

* Update Nix dependency hash for plugin peer metadata

* Group plugin APIs under client and server entry trees

* Resolve plugin type dependencies through declarations

* Validate declarations for implicit plugin type imports

* Preserve optional imports and validate declaration references

* Refresh Nix hash for plugin declaration resolver

* Canonicalize plugin paths consistently on Windows

* Normalize plugin ownership paths across resolver boundaries

---------

Co-authored-by: liujin0506 <liujin0506@qq.com>
Co-authored-by: Mohamed Boudra <boudra.moha@gmail.com>

scripts/ci-workflow.test.mjs

@@ -169,7 +169,14 @@ test("PR routing declares stable behavior ownership", () => {
       "packages/app/package.json",
     ],
     app: ["packages/app/**", "packages/expo-two-way-audio/**"],
-    sdk: ["packages/client/**", "packages/highlight/**", "packages/protocol/**"],
+    sdk: [
+      "packages/plugin/**",
+      "plugin-examples/**",
+      "public-docs/plugins/v0.8/**",
+      "packages/client/**",
+      "packages/highlight/**",
+      "packages/protocol/**",
+    ],
     browser: [
       "packages/server/src/server/agent/provider-snapshot-manager.ts",
       "packages/server/src/server/session/provider/provider-catalog-session.ts",
@@ -182,7 +189,7 @@ test("PR routing declares stable behavior ownership", () => {
       "packages/server/src/server/agent/plugin-provider.ts",
       "packages/server/src/server/plugins/{index,plugin-process,plugin-process-protocol,runtime}.ts",
       "packages/server/src/executable-resolution/**",
-      "packages/plugin/src/provider.ts",
+      "packages/plugin/src/server/provider.ts",
       "packages/app/src/!(desktop)/**",
       "packages/app/e2e/browser/**",
       "packages/app/e2e/support/**",
@@ -262,7 +269,7 @@ test("browser and desktop tests have exclusive, directory-owned suites", () => {
     "packages/server/src/server/agent/plugin-provider.ts",
     "packages/server/src/server/plugins/{index,plugin-process,plugin-process-protocol,runtime}.ts",
     "packages/server/src/executable-resolution/**",
-    "packages/plugin/src/provider.ts",
+    "packages/plugin/src/server/provider.ts",
     "packages/app/src/!(desktop)/**",
     "packages/app/e2e/browser/**",
     "packages/app/e2e/support/**",