nmap inventory plugin: add skip_host_discovery option (#11955)

* feat(nmap inventory): add skip_host_discovery option (-Pn)

Adds skip_host_discovery option to suppress nmap's default host
discovery probes (TCP SYN to 80/443), which caused unexpected traffic
when scanning remote hosts over VPN or through firewalls.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* changelog: add fragment for nmap skip_host_discovery option (#11955)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

changelogs/fragments/11955-nmap-skip-host-discovery.yml

@@ -0,0 +1,4 @@
+minor_changes:
+  - nmap inventory plugin - add ``skip_host_discovery`` option to skip nmap host discovery phase (``-Pn``)
+    (https://github.com/ansible-collections/community.general/issues/7893,
+    https://github.com/ansible-collections/community.general/pull/11955).

plugins/inventory/nmap.py

@@ -95,6 +95,16 @@ options:
     type: boolean
     default: true
     version_added: 7.4.0
+  skip_host_discovery:
+    description:
+      - Skip nmap host discovery phase and treat all hosts as online (C(-Pn)).
+      - Useful when scanning remote hosts over VPN or through firewalls where nmap's default discovery probes
+        (TCP SYN to ports 80/443) are blocked but the target port is open.
+      - When V(false) (default), nmap performs host discovery before port scanning, which may send packets
+        to ports 80 and 443 regardless of the O(port) setting.
+    type: boolean
+    default: false
+    version_added: 13.0.0
   set_name_variable:
     description:
       - Set the C(name) variable for each host.
@@ -264,6 +274,9 @@ class InventoryModule(BaseInventoryPlugin, Constructable, Cacheable):
             if not self.get_option("use_arp_ping"):
                 cmd.append("--disable-arp-ping")
 
+            if self.get_option("skip_host_discovery"):
+                cmd.append("-Pn")
+
             cmd.append(self.get_option("address"))
             try:
                 # execute