Update documentation to clarify boot hook context and plugin requirements for shared infrastructure

Author: biximilien

docs/adrs/025_optional_infrastructure_plugins.md

@@ -36,6 +36,8 @@ _Boot behavior_:
 
 Plugin `boot` is a configuration boundary. Boot failures should fail fast so the bot does not continue with partially initialized required infrastructure. Runtime hooks such as `message`, `ready`, moderation observations, command contribution, and strategy contribution may remain isolated so one plugin hook failure does not stop unrelated processing.
 
+The `boot` hook receives shared runtime context as keyword arguments, currently `app:`, `bot:`, and `plugin_registry:`. Plugins should require only the context they need. This keeps lifecycle dependencies explicit without forcing every plugin to depend on the Discord bot, application object, or registry.
+
 _Consequences_:
 
 - Keeps optional services optional without obscuring dependencies

docs/architecture.md

@@ -179,6 +179,8 @@ Current hook types include:
 - command contribution hook: `commands`
 - optional infrastructure capabilities through `capabilities` and `PluginRegistry#capability`
 
+The `boot` hook receives the shared runtime context: `app:`, `bot:`, and `plugin_registry:`. Plugins should require only the keyword arguments they need. For example, infrastructure plugins usually need `app:` or `plugin_registry:`, while delivery-oriented plugins may need `bot:` to interact with Discord outside a single message event.
+
 Plugins that provide shared optional infrastructure should expose it as a named capability, such as `postgres_connection` or `ai_provider`. Domain plugins should consume those capabilities through the registry instead of depending directly on a concrete infrastructure plugin class. Existing named registry helpers may remain as compatibility shims for common capabilities.
 
 The public Ruby namespace is `OpenModBot`.

lib/plugin.rb

@@ -1,5 +1,7 @@
 module OpenModBot
   class Plugin
+    # Boot receives the shared runtime context: app:, bot:, and plugin_registry:.
+    # Concrete plugins should require only the keyword arguments they actually use.
     def boot(**); end
 
     def ready(**); end