fix(packaging): move templates/ into decnet/ package so they ship with pip install

The docker build contexts and syslog_bridge.py lived at repo root, which
meant setuptools (include = ["decnet*"]) never shipped them. Agents
installed via `pip install $RELEASE_DIR` got site-packages/decnet/** but no
templates/, so every deploy blew up in deployer._sync_logging_helper with
FileNotFoundError on templates/syslog_bridge.py.

Move templates/ -> decnet/templates/ and declare it as setuptools
package-data. Path resolutions in services/*.py and engine/deployer.py drop
one .parent since templates now lives beside the code. Test fixtures,
bandit exclude path, and coverage omit glob updated to match.

decnet/templates/cowrie/honeyfs/etc/shadow

@@ -0,0 +1,36 @@
+root:$6$rounds=4096$randomsalt$hashed_root_password:19000:0:99999:7:::
+daemon:*:19000:0:99999:7:::
+bin:*:19000:0:99999:7:::
+sys:*:19000:0:99999:7:::
+sync:*:19000:0:99999:7:::
+games:*:19000:0:99999:7:::
+man:*:19000:0:99999:7:::
+lp:*:19000:0:99999:7:::
+mail:*:19000:0:99999:7:::
+news:*:19000:0:99999:7:::
+uucp:*:19000:0:99999:7:::
+proxy:*:19000:0:99999:7:::
+www-data:*:19000:0:99999:7:::
+backup:*:19000:0:99999:7:::
+list:*:19000:0:99999:7:::
+irc:*:19000:0:99999:7:::
+gnats:*:19000:0:99999:7:::
+nobody:*:19000:0:99999:7:::
+systemd-network:*:19000:0:99999:7:::
+systemd-resolve:*:19000:0:99999:7:::
+messagebus:*:19000:0:99999:7:::
+systemd-timesync:*:19000:0:99999:7:::
+syslog:*:19000:0:99999:7:::
+_apt:*:19000:0:99999:7:::
+tss:*:19000:0:99999:7:::
+uuidd:*:19000:0:99999:7:::
+tcpdump:*:19000:0:99999:7:::
+landscape:*:19000:0:99999:7:::
+pollinate:*:19000:0:99999:7:::
+fwupd-refresh:*:19000:0:99999:7:::
+usbmux:*:19000:0:99999:7:::
+sshd:*:19000:0:99999:7:::
+systemd-coredump:!!:19000::::::
+lxd:!:19000::::::
+mysql:!:19000:0:99999:7:::
+admin:$6$rounds=4096$xyz123$hashed_admin_password:19000:0:99999:7:::