Move plugins to manifest, pin Docker version, add Makefile

- Add plugins.txt listing all plugins for reproducible installs
- Add Makefile with setup/start/stop/install-plugins targets
- Remove user/plugins/ from git tracking
- Pin Docker image to 1.7.49.5-ls244

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

plugins/email/api-docs/chapter.md

@@ -1,26 +0,0 @@
----
-title: Email
-template: chapter
-description: Send emails via the Grav API
-taxonomy:
-    category:
-        - docs
----
-
-The Email API allows you to send ad-hoc emails and test your email configuration programmatically. These endpoints are registered by the Email plugin via the Grav API plugin's extensibility system.
-
-## Requirements
-
-- [Grav API Plugin](https://github.com/getgrav/grav-plugin-api) must be installed and enabled
-- Email plugin must be installed, enabled, and configured with a valid mailer
-
-## Authentication
-
-All email endpoints require the `api.system.write` permission.
-
-## Available Operations
-
-| Method | Endpoint | Description |
-|--------|----------|-------------|
-| POST | `/email/send` | Send an ad-hoc email |
-| POST | `/email/test` | Send a test email to verify configuration |