fix(ansible): resolve LTE failover data-plane bug on BroadMobi BM806C

The embedded BroadMobi BM806C modem (Qualcomm MDM9225, firmware
M1.2.0_E1.0.1_A1.1.8) in the D-Link DWR-921 C1 has two independent
firmware bugs that together break the QMI data plane:

1.  Modem accepts 802.3 framing but its 802.3 path is buggy — downlink
    frames never reach the host kernel. raw-ip framing works.

2.  qmish calls uqmi --start-network --apn <foo>, which triggers
    FS#1363: the modem establishes a phantom bearer that gets IP
    addresses but has no working data path. Using --start-network
    --profile <N> (referencing a pre-configured NVRAM profile with
    the same APN) works correctly.

Fixes applied:

- qmish patches (3x community.openwrt.lineinfile):
  * Replace --set-data-format 802.3 with raw-ip
  * Replace --wda-set-data-format 802.3 with raw-ip
  * Bracket raw_ip sysfs write with ip link down/up (kernel rejects
    write with -EBUSY when wwan0 is already up)
- Modem NVRAM: create/modify profile 2 (internetipv6, ipv6) for the
  IPv6 APN — profile 1 is already managed by qmish's --modify-profile
- UCI wwan: add profile=1 and v6profile=2 so qmish uses --start-network
  --profile instead of --apn on both the v4 and v6 legs
- Firewall: add wwan zone (input REJECT, output ACCEPT, forward REJECT)
  and Allow-ICMPv6-wwan rule
- main.yml: reorder — packages (including usb-modeswitch) now run
  before wwan setup, so the modem is out of EDL mode when wwan.yml
  queries it for profile creation

See docs/wwan-bm806c-qmi-workaround.md for the full diagnosis
(what we ruled out, how we confirmed, manual setup steps, component
versions, future upstreaming).

ansible/roles/openwrt/tasks/main.yml

@@ -5,9 +5,19 @@
 - name: System configuration
   ansible.builtin.import_tasks: system.yml
 
+# Packages must be installed before wwan.yml — usb-modeswitch is what triggers
+# the modem out of EDL mode (05c6:9008 → 2020:2033 QMI), and uqmi/luci-proto-qmi
+# provide the tools used downstream.
+- name: Package management
+  ansible.builtin.import_tasks: packages.yml
+  when: openwrt_packages | length > 0
+
 - name: Network configuration
   ansible.builtin.import_tasks: network.yml
 
+- name: WWAN modem configuration
+  ansible.builtin.import_tasks: wwan.yml
+
 - name: Firewall configuration
   ansible.builtin.import_tasks: firewall.yml
 
@@ -16,7 +26,3 @@
 
 - name: LED configuration
   ansible.builtin.import_tasks: led.yml
-
-- name: Package management
-  ansible.builtin.import_tasks: packages.yml
-  when: openwrt_packages | length > 0