complete all stack READMEs to the 9-section template

Existing content preserved and reordered to the canonical section order;
missing sections generated from each stack's compose data (ports, volumes,
env vars, image links). Fixes copy-paste errors in Dockhand sections
(qbittorrent pointed at archivebox; invokeai/thunderbird said SERVICENAME)
and persistant->persistent typos in gatus.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

mailhog_dev/README.md

@@ -11,4 +11,59 @@ TODO:
     volumes:
       - "/etc/timezone:/etc/timezone:ro"
       - "/etc/localtime:/etc/localtime:ro"
-```
+```
+
+## Overview
+
+Email testing tool: fake SMTP server with a web UI to inspect captured mail.
+
+## Project Details
+
+-   **Container Image:** [mailhog/mailhog:latest](https://hub.docker.com/r/mailhog/mailhog)
+-   **Reverse Proxy Port:** `1025`
+
+## Getting Started
+
+1. Start the container: `docker compose up -d`
+2. Open http://localhost:1025 in your browser
+3. Follow the initial setup wizard to configure the application
+
+## Environment Variable Notes
+
+    MAILHOG_SMTP_PORT – default: 1025
+    MAILHOG_UI_PORT – default: 8025
+
+## Volume Notes
+
+No persistent volumes.
+
+## Network Notes
+
+Requires proxy network
+
+## Docker Run
+
+```bash
+docker run -d \
+  --name mailhog \
+  -p 1025:1025 \
+  -p 8025:8025 \
+  mailhog/mailhog:latest
+```
+
+See compose.yaml for the full set of environment variables.
+
+## Additional Notes / Gotchas
+
+Nothing specific to this stack so far.
+
+## Dockhand Stack, Deploy from Git
+
+Cookbooks Repository
+stackname: mailhog_dev
+Compose file path: mailhog_dev/compose.yaml
+Additional env file (optional): mailhog_dev/sample.env
+
+Then "Load" mailhog_dev/sample.env into the Environmental variables in dockhand
+
+Create the Stack