chore: rework plugin readmes, json changelogs and standalone repo setup

plugins/ai/CONTRIBUTING.md

@@ -0,0 +1,37 @@
+# Contributing to AI Assistant
+
+## Development
+
+```bash
+npm run build      # build into dist/
+npm run test       # run this plugin's tests
+npm run typecheck  # type-check this plugin
+npm run validate   # check manifest.json
+npm run format     # format the code with Prettier
+```
+
+## Settings
+
+### Admin
+
+- **AI assistant:** let users turn the assistant on. While this is off it is hidden and blocked for everyone
+- **Allowed private AI hosts:** hosts on your private network a provider may point at, such as a self-hosted Ollama
+
+### User
+
+- **Enable the AI assistant:** turn the assistant on for yourself
+- **Allow read-only diagnostic commands:** let the assistant run safe commands without asking
+- **Providers:** your AI providers, models and API keys
+
+### Host
+
+- **Enable AI Assistant:** let the assistant help in this host's terminal. Off by default
+
+## Permissions
+
+- `ai.use`: use the assistant. Admins and users have it by default.
+- `ai.manage_providers`: add, edit and remove AI providers and their API keys. Admins and users have it by default.
+- `ai.apply_proposals`: let the assistant carry out the changes it suggests. Admins and users have it by default.
+- `ai.services.use`: let other features call the assistant for you. Admins and users have it by default.
+- `ai.secrets.share`: let other features use the stored API key without seeing it. Admins and users have it by default.
+- `ai.agents`: run coding agents on SSH hosts. Only admins have it by default.