Customised Analytics for admins and users (#4687)

Adds granular privacy controls for analytics - splits single
enableAnalytics toggle into separate PostHog and Scarf controls with
improved admin
  UX.

  Backend Changes

  Configuration (ApplicationProperties.java)
  - Added enablePosthog and enableScarf boolean fields
- New methods: isPosthogEnabled(), isScarfEnabled() (null = enabled when
analytics is on)

  Services
- PostHogService: Now checks isPosthogEnabled() instead of
isAnalyticsEnabled()
  - ConfigController: Exposes new flags via API
- SettingsController: Changed endpoint from @RequestBody to
@RequestParam

  Frontend Changes

  Architecture
- Converted useAppConfig hook → AppConfigContext provider for global
access
  - Added refetch() method for config updates without reload

  New Features
1. AdminAnalyticsChoiceModal: First-launch modal when enableAnalytics
=== null
    - Enable/disable without editing YAML
    - Includes documentation link
  2. Scarf Tracking System: Modular utility with React hook wrapper
    - Respects config + per-service cookie consent
    - Works from any code location (React or vanilla JS)
3. Enhanced Cookie Consent: Per-service toggles (PostHog and Scarf
separate)

  Integration
  - App.tsx: Added AppConfigProvider + scarf initializer
  - HomePage.tsx: Shows admin modal when needed
  - index.tsx: PostHog opt-out by default, service-level consent

  Key Benefits

✅ Backward compatible (null defaults to enabled)
✅ Granular control per analytics service
✅ First-launch admin modal (no YAML editing)
✅ Privacy-focused with opt-out defaults
✅ API-based config updates

---------

Co-authored-by: Connor Yoh <connor@stirlingpdf.com>

app/common/src/main/java/stirling/software/common/model/ApplicationProperties.java

@@ -355,6 +355,8 @@ public class ApplicationProperties {
         private String tessdataDir;
         private Boolean enableAlphaFunctionality;
         private Boolean enableAnalytics;
+        private Boolean enablePosthog;
+        private Boolean enableScarf;
         private Datasource datasource;
         private Boolean disableSanitize;
         private int maxDPI;
@@ -368,6 +370,18 @@ public class ApplicationProperties {
         public boolean isAnalyticsEnabled() {
             return this.getEnableAnalytics() != null && this.getEnableAnalytics();
         }
+
+        public boolean isPosthogEnabled() {
+            // Treat null as enabled when analytics is enabled
+            return this.isAnalyticsEnabled()
+                    && (this.getEnablePosthog() == null || this.getEnablePosthog());
+        }
+
+        public boolean isScarfEnabled() {
+            // Treat null as enabled when analytics is enabled
+            return this.isAnalyticsEnabled()
+                    && (this.getEnableScarf() == null || this.getEnableScarf());
+        }
     }
 
     @Data

app/common/src/main/java/stirling/software/common/service/PostHogService.java

@@ -56,7 +56,7 @@ public class PostHogService {
     }
 
     private void captureSystemInfo() {
-        if (!applicationProperties.getSystem().isAnalyticsEnabled()) {
+        if (!applicationProperties.getSystem().isPosthogEnabled()) {
             return;
         }
         try {
@@ -67,7 +67,7 @@ public class PostHogService {
     }
 
     public void captureEvent(String eventName, Map<String, Object> properties) {
-        if (!applicationProperties.getSystem().isAnalyticsEnabled()) {
+        if (!applicationProperties.getSystem().isPosthogEnabled()) {
             return;
         }
 
@@ -325,6 +325,14 @@ public class PostHogService {
                 properties,
                 "system_enableAnalytics",
                 applicationProperties.getSystem().isAnalyticsEnabled());
+        addIfNotEmpty(
+                properties,
+                "system_enablePosthog",
+                applicationProperties.getSystem().isPosthogEnabled());
+        addIfNotEmpty(
+                properties,
+                "system_enableScarf",
+                applicationProperties.getSystem().isScarfEnabled());
 
         // Capture UI properties
         addIfNotEmpty(properties, "ui_appName", applicationProperties.getUi().getAppName());