feat(guru-scan): fix exit code capture, add GURUSCAN_RESULT_JSON reporting, pre-scan hardening

Exit code fix: add $proc.Handle caching after Start-Process -PassThru to prevent
the handle from being released before ExitCode is readable (known PS5.1 bug).

GuruRMM reporting: launcher now finds results.json after each scan and emits
GURUSCAN_RESULT_JSON:<compressed> to stdout. Agent CommandResult captures it;
server stores it in commands.stdout for retrieval via GET /api/commands/:id.

Pre-scan hardening:
- Pre-flight EXE check: warns about missing scanner binaries before run starts
- Windows Defender exclusions added for scanner/log paths before scan, removed after

AdwCleaner: add /path {LOG_ROOT} arg so logs write directly to scan log root;
update log_src to {LOG_ROOT}\Logs to match.

HitmanPro: add /quiet to scan and clean args to suppress GUI in headless runs.

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

projects/msp-tools/guru-scan/scanners.json

@@ -21,7 +21,8 @@
       "service_names": [],
       "hitmanpro_trial_reset": false,
       "whitelist_arg": null,
-      "wait_on_process": null
+      "wait_on_process": null,
+      "session0_compatible": true
     },
     {
       "name": "AdwCleaner",
@@ -33,18 +34,19 @@
       "download_url": "https://adwcleaner.malwarebytes.com/adwcleaner?channel=release",
       "manual_download": true,
       "manual_download_note": "Malwarebytes blocks automated downloads; download manually from https://www.malwarebytes.com/adwcleaner",
-      "scan_args": ["/eula", "/scan", "/noreboot"],
-      "clean_args": ["/eula", "/clean", "/noreboot"],
-      "log_src": "C:\\AdwCleaner\\Logs",
+      "scan_args": ["/eula", "/scan", "/noreboot", "/path", "{LOG_ROOT}"],
+      "clean_args": ["/eula", "/clean", "/noreboot", "/path", "{LOG_ROOT}"],
+      "log_src": "{LOG_ROOT}\\Logs",
       "timeout_min": 60,
       "randomize_exe": false,
       "pre_close_processes": [],
       "pre_clean_paths": ["C:\\AdwCleaner"],
-      "post_clean_paths": ["C:\\AdwCleaner"],
+      "post_clean_paths": [],
       "service_names": ["AdwCleanerSvc"],
       "hitmanpro_trial_reset": false,
       "whitelist_arg": null,
-      "wait_on_process": "AdwCleaner"
+      "wait_on_process": "AdwCleaner",
+      "session0_compatible": false
     },
     {
       "name": "Emsisoft",
@@ -94,7 +96,8 @@
       "service_names": [],
       "hitmanpro_trial_reset": false,
       "whitelist_arg": "emsisoft",
-      "wait_on_process": "a2cmd"
+      "wait_on_process": "a2cmd",
+      "session0_compatible": true
     },
     {
       "name": "HitmanPro",
@@ -109,12 +112,14 @@
       "scan_args": [
         "/noinstall",
         "/scan",
+        "/quiet",
         "/log=\"{LOG_ROOT}\\HitmanPro_Scan_Log.txt\"",
         "/excludelist=\"C:\\GuruScan\\whitelist.txt\""
       ],
       "clean_args": [
         "/noinstall",
         "/clean",
+        "/quiet",
         "/log=\"{LOG_ROOT}\\HitmanPro_Scan_Log.txt\"",
         "/excludelist=\"C:\\GuruScan\\whitelist.txt\""
       ],
@@ -137,7 +142,8 @@
       "service_names": [],
       "hitmanpro_trial_reset": true,
       "whitelist_arg": "hitmanpro",
-      "wait_on_process": "HitmanPro_x64"
+      "wait_on_process": "HitmanPro_x64",
+      "session0_compatible": true
     }
   ]
 }