feat: move asciinema to dev stack under asciinema.dev.pivoine.art

- Moved asciinema service from standalone stack to dev/compose.yaml
- Updated hostname from asciinema.pivoine.art to asciinema.dev.pivoine.art
- Updated environment variables to use DEV_ASCIINEMA_ prefix
- Updated restic backup volume reference (asciinema_data -> dev_asciinema_data)
- Moved custom.exs to dev/asciinema-custom.exs
- Removed standalone asciinema/compose.yaml directory
- Container name changes from asciinema_app to dev_asciinema
- Volume name changes from asciinema_data to dev_asciinema_data
- Preserved admin interface at admin.asciinema.dev.pivoine.art with Basic Auth

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

dev/asciinema-custom.exs

@@ -0,0 +1,17 @@
+import Config
+
+# Configure Swoosh SMTP adapter to skip TLS certificate verification
+# This is needed for IONOS SMTP server which has certificate key usage issues
+config :asciinema, Asciinema.Emails.Mailer,
+  adapter: Swoosh.Adapters.SMTP,
+  relay: System.get_env("SMTP_HOST"),
+  username: System.get_env("SMTP_USERNAME"),
+  password: System.get_env("SMTP_PASSWORD"),
+  port: System.get_env("SMTP_PORT") || 587,
+  tls: :always,
+  auth: :always,
+  ssl: false,
+  tls_options: [
+    verify: :verify_none,
+    versions: [:"tlsv1.2", :"tlsv1.3"]
+  ]