feat(sdk): pluginRoot officiel exposé dans activate(ctx) — #285 (src/runtime: champ pluginRoot = racine du package installé; docs activation-context/commands-and-feedback/services/manifest réécrits du constat d'absence vers le contrat d'usage officiel — runCommand reste project-scoped, pluginRoot utilisable dans command/args, substitution manifest ${pluginRoot}/${appDataDir} inchangée pour mcpServers; exemple hello-plugin: script packagé scripts/hello-task.mjs consommé via ctx.pluginRoot, packaging étendu; QA verte: npm run check — build, typecheck:examples, package:hello-plugin, artefact zip vérifié)

docs/activation-context.md

@@ -6,7 +6,10 @@ The plugin entrypoint exports `activate(ctx)`.
 import type { ActivateContext, IdeAPluginModule } from "@idea/plugin-sdk";
 
 export function activate(ctx: ActivateContext): void {
-  ctx.logger.info("activated", { pluginId: ctx.pluginId });
+  ctx.logger.info("activated", {
+    pluginId: ctx.pluginId,
+    pluginRoot: ctx.pluginRoot
+  });
 }
 
 export default { activate } satisfies IdeAPluginModule;
@@ -28,6 +31,7 @@ focused project at invocation/render time.
 ## Context Fields
 
 - `pluginId`: host-provided plugin identity.
+- `pluginRoot`: absolute host-local path to the active installed plugin package.
 - `logger`: `debug`, `info`, `warn`, `error`.
 - `subscriptions`: push disposables returned by command/layout/watch
   registrations.
@@ -41,11 +45,11 @@ focused project at invocation/render time.
 The context never exposes internal IdeA gateways or Tauri commands. Use
 `ctx.services` and the registration APIs instead.
 
-`ActivateContext` does not expose the plugin installation directory, package
-root, archive root or a file URL that plugins can convert into a local path.
-Plugin runtime code must treat packaged files as unavailable to
-`ctx.services.tasks.runCommand()` unless a dedicated public SDK API documents
-otherwise. Workspace services resolve project-owned paths only.
+`pluginRoot` identifies the committed package currently loaded by IdeA. It is
+not the original source directory or archive path and may change after reinstall.
+Treat it as read-only, do not persist it, and resolve packaged scripts/assets
+under it only while the plugin is active. Workspace services remain confined to
+project-owned paths.
 
 ## Disposal