jmri: move udev symlinks to /dev/jmri-* (flat, JMRI-enumerable)

/dev/jmri/ subdirectory is invisible to JMRI's device scanner.
Symlinks must live directly in /dev to appear in the port dropdown.

ansible/roles/jmri/tasks/main.yml

@@ -47,12 +47,6 @@
 # Phase 1 — Stable USB device symlinks
 # Creates /dev/jmri/loconet and /dev/jmri/nce via udev ID_SERIAL matching.
 # ---------------------------------------------------------------------------
-- name: Create /dev/jmri directory (udev will populate it)
-  ansible.builtin.file:
-    path: /dev/jmri
-    state: directory
-    mode: '0755'
-
 - name: Deploy udev rules for JMRI USB devices
   ansible.builtin.template:
     src: 99-jmri-devices.rules.j2