feat: convert tmux monitoring into a plugin (B10)

plugins/tmux-monitor/CHANGELOG.md

@@ -0,0 +1,14 @@
+# Changelog
+
+## 1.0.0
+
+Bundled with Termix 2.9.0.
+
+- Tmux monitoring moved out of core's own server on port 30010 and now serves
+  under `/plugin-api/tmux-monitor` through core's connect pipeline.
+- Owns its data: core's `tmux_session_tags` table is renamed to
+  `p_tmux_monitor_session_tags` on first activation, and each host's monitor
+  switch moves into this plugin's host settings.
+- New `tmux-monitor.use` permission, given to the admin and user roles.
+- Offers `tmux.sessions` to other plugins, so the terminal can attach to,
+  create and wait for tmux sessions without importing this plugin.