feat(send): add role for self-hosted Send file-share service

Deploys timvisee/send with a Redis backend behind Traefik. Supports
local-disk or S3 storage (e.g. via the garage role). Uses the shared
`*_domains` list convention so the router can accept internal *.int.*
names alongside the canonical BASE_URL host.

roles/send/defaults/main.yml

@@ -0,0 +1,53 @@
+#SPDX-License-Identifier: MIT-0
+---
+# defaults file for send
+
+# Base directory configuration (inherited from base role or defined here)
+docker_compose_base_dir: /etc/docker/compose
+docker_volume_base_dir: /srv/data
+
+# Send-specific configuration
+send_service_name: send
+send_docker_compose_dir: "{{ docker_compose_base_dir }}/{{ send_service_name }}"
+send_docker_volume_dir: "{{ docker_volume_base_dir }}/{{ send_service_name }}"
+
+# Service configuration
+# FQDNs the send router accepts. The first entry is the canonical
+# domain (used as BASE_URL); further entries cover internal *.int.*
+# names so backend uploads can hit us without hairpinning via DMZ.
+send_domains:
+  - "send.local.test"
+send_image: "registry.gitlab.com/timvisee/send:latest"
+send_port: 1443
+send_extra_hosts: []
+
+# Redis backend
+send_redis_image: "redis:7-alpine"
+send_redis_service_name: "send-redis"
+
+# Send application configuration
+# https://github.com/timvisee/send/blob/master/server/config.js
+send_max_file_size: 1073741824   # 1 GiB in bytes
+send_default_downloads: 1
+send_max_downloads: 100
+send_default_expire_seconds: 86400      # 24h
+send_max_expire_seconds: 604800         # 7d
+send_max_files_per_archive: 64
+send_download_counts: "1,2,3,4,5,20,50,100"
+send_expire_times_seconds: "300,3600,86400,604800"
+
+# Storage backend: "local" (volume) or "s3"
+send_storage_backend: "local"
+
+# S3 backend (only used when send_storage_backend == "s3")
+send_s3_endpoint: ""
+send_s3_bucket: ""
+send_s3_region: "us-east-1"
+send_s3_access_key: ""
+send_s3_secret_key: ""
+send_s3_use_path_style: true
+
+# Traefik configuration
+send_traefik_network: "proxy"
+send_internal_network: "send_internal"
+send_use_ssl: true