Manages the Apache 2.4 httpd process lifecycle for NKS WebDev Console and generates per-site vhost files from Scriban templates.

• Validates httpd.conf syntax before starting.
• Spawns the bundled httpd.exe from ~/.wdc/binaries/apache/<ver>/ with a WDC-managed config root.
• Generates <domain>.conf vhost files under ~/.wdc/apache/vhosts/ from Templates/vhost.scriban.
• Reloads gracefully (httpd -k restart) on site changes.
• Publishes CPU / RAM / request-rate metrics over the plugin event bus.

• Binary: discovered from binaries/apache/<semver>/bin/httpd.exe.
• Config root: ~/.wdc/apache/conf/httpd.conf (regenerated on apply).
• Vhost root: ~/.wdc/apache/vhosts/*.conf (one per WDC site).
• Log dir: ~/.wdc/apache/logs/ (access + error logs per site).

• service.state.changed (starting → running → stopped / error)
• service.metrics (cpu / mem / req-per-min when access log parses)
• service.log.line (tail of error.log)
• site.validate.* (before and after each vhost regen)

None — Apache is a pure service plugin. Site-level operations go through the daemon's /api/sites/* routes which call into ApachePlugin via DI.

• Service card on Dashboard
• Log viewer
• Config editor for httpd.conf
• Version switcher across installed Apache builds

Unit tests live in tests/NKS.WebDevConsole.Daemon.Tests (in the main WDC repo for now — will move here when plugin tests migrate).