docs(sdk): plugin minimal en dossier + hot reload documentés — manifest (arborescence minimale idea-plugin.json/package.json/tsconfig/src/dist, install depuis dossier), packaging-distribution (procédure hot reload directory install + idea_plugin_reload + limites UI React), README (lien packaging hot reload)

docs/packaging-distribution.md

@@ -74,3 +74,55 @@ npm run package:hello-plugin
 
 The resulting archive has no wrapping parent directory and is ready for IdeA's
 plugin installer.
+
+## Hot Reload During Development
+
+Install the plugin from a directory when you want IdeA to hot-reload changes
+without restarting the app.
+
+In IdeA, open `Paramètres > Plugins`, choose `Installer depuis un dossier…`,
+and select the plugin source directory. That directory must contain
+`idea-plugin.json` at its root, and the manifest `main` field must point to the
+built entrypoint that exists inside the same directory, for example
+`dist/index.js`.
+
+```text
+hello-plugin/
+├── idea-plugin.json
+├── package.json
+└── dist/
+    ├── index.js
+    └── core/
+        └── layout.js
+```
+
+After editing plugin source files, rebuild the plugin output first:
+
+```sh
+npm run build
+```
+
+Then ask an IdeA agent that has the plugin administration tool available to run
+`idea_plugin_reload` with the installed plugin id:
+
+```json
+{
+  "pluginId": "com.example.hello-plugin"
+}
+```
+
+The reload uses the recorded directory source from the plugin registry. It
+re-reads and validates the manifest, recalculates the package hash, updates the
+installed package, emits `plugin_reloaded`, and reconciles plugin MCP servers.
+It does not accept an arbitrary path at reload time; install from the intended
+development directory first.
+
+Do not install from the ZIP archive for a development loop that needs hot
+reload. Archive installs are fixed package snapshots. They are appropriate for
+distribution, but the reload command is only defined for plugins installed from
+a directory source.
+
+Current limitation: backend registry state and plugin MCP/tool contributions are
+reloaded without restarting IdeA. Frontend React contributions that are already
+loaded in the current UI session may keep their existing module instance until
+the relevant plugin surface is recreated or the app session is restarted.