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>

plugin-examples/linear/index.client.ts

@@ -1,4 +1,4 @@
-import type { PluginClientContext } from "@getpaseo/plugin";
+import type { PluginClientContext } from "@getpaseo/plugin/client";
 import { issueAttachments } from "./shared/issues";
 
 export default function contribute(client: PluginClientContext) {

plugin-examples/linear/index.server.ts

@@ -1,4 +1,4 @@
-import type { PluginServerContext } from "@getpaseo/plugin";
+import type { PluginServerContext } from "@getpaseo/plugin/server";
 import { searchIssues } from "./server/issues";
 import { searchIssuesRpc } from "./shared/issues";