Upgrade borgmatic 2.0.13 → 2.1.3 on indri

Upgrade already applied via mise/pipx. Key upstream changes:
- Borg warnings handling improved (file-not-found reverted to warning in 2.1.3)
- Memory and performance improvements in pre-backup validation
- source_directories_must_exist default now true (already set in our config)

Dry-run verified against both sifaka and borgbase repositories.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/changelog.d/upgrade-borgmatic-2.1.3.infra.md

@@ -0,0 +1 @@
+Upgrade borgmatic from 2.0.13 to 2.1.3 on indri (improved borg warning handling, memory/performance improvements)

service-versions.yaml

@@ -283,9 +283,10 @@ services:
 
   - name: borgmatic
     type: ansible
-    last-reviewed: null
-    current-version: null
+    last-reviewed: 2026-03-16
+    current-version: "2.1.3"
     upstream-source: https://github.com/borgmatic-collective/borgmatic/releases
+    notes: Installed via mise (pipx), not managed by Ansible role
 
   - name: jellyfin
     type: ansible