jmri: deploy udev rules for stable /dev/jmri/* symlinks

Rules were documented but never deployed — /dev/jmri/nce was missing
entirely, only /dev/jmri/loconet existed (created manually).

Adds:
- templates/99-jmri-devices.rules.j2: LocoBuffer-NG -> loconet,
  NCE Power Pro (Microchip CDC) -> nce
- Task to deploy rules + trigger udev settle
- Trigger udev handler (reload-rules alone is insufficient)

ansible/roles/jmri/tasks/main.yml

@@ -43,6 +43,27 @@
     groups: dialout
     append: true
 
+# ---------------------------------------------------------------------------
+# 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
+    dest: /etc/udev/rules.d/99-jmri-devices.rules
+    owner: root
+    group: root
+    mode: '0644'
+  notify:
+    - Reload udev
+    - Trigger udev
+
 
 # ---------------------------------------------------------------------------
 # Phase 2 — LocoNet traffic monitor