fix(coraza-spoe): collapse args to one line + ensure trailing LF on spoe cfg

Two HAProxy parse errors caught in staging functional test:

1. coraza-spoe.cfg:39 'args': missing fetch method
   The args directive had backslash line continuations. HAProxy doesn't
   support those in SPOE configs — args must be one physical line.
   Collapsed to a single line.

2. coraza-spoe.cfg:50 Missing LF on last line
   Same trailing-LF issue we hit on haproxy.cfg one commit ago. The
   Jinja2 template ends with content rather than a newline, and write()
   doesn't add one. Belt-and-suspenders: explicitly append '\n' before
   writing if not already there.

After this commit HAProxy validates the generated config cleanly. Will
verify on staging now (combined SPOE injection + fail-open + active
attack-detection tests).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

haproxy_manager.py

@@ -1863,6 +1863,12 @@ backend default-backend
             coraza_spoe_cfg = template_env.get_template(
                 'hap_coraza_spoe_engine.tpl'
             ).render()
+            # HAProxy also rejects this file without a trailing LF
+            # ("Missing LF on last line"). Belt-and-suspenders — even if the
+            # template ends with a newline, Jinja2 can trim it depending on
+            # how the file was authored.
+            if not coraza_spoe_cfg.endswith('\n'):
+                coraza_spoe_cfg += '\n'
             coraza_spoe_path = '/etc/haproxy/coraza-spoe.cfg'
             with open(coraza_spoe_path, 'w') as f:
                 f.write(coraza_spoe_cfg)