feat: Wire up analytics hooks in MainActivity and AdminActivity

- Log session_start on app launch
- Log page_view on every page load
- Log idle_reset when idle timer fires
- Log session_end on app close
- Log admin_access (success/fail) on PIN verification

app/src/main/kotlin/farm/hobbs/kioskbrowser/AdminActivity.kt

@@ -6,6 +6,7 @@ import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.app.AppCompatActivity
 import androidx.datastore.preferences.core.edit
 import androidx.datastore.preferences.core.stringPreferencesKey
+import farm.hobbs.kioskbrowser.analytics.AnalyticsManager
 import farm.hobbs.kioskbrowser.databinding.ActivityAdminBinding
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.runBlocking
@@ -15,11 +16,14 @@ import android.widget.EditText
 class AdminActivity : AppCompatActivity() {
 
     private lateinit var binding: ActivityAdminBinding
+    private lateinit var analytics: AnalyticsManager
     private val adminPin = "1234" // Default PIN - should be configurable
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         
+        analytics = AnalyticsManager.getInstance(this)
+        
         // Require PIN before showing settings
         showPinDialog()
     }
@@ -36,8 +40,10 @@ class AdminActivity : AppCompatActivity() {
             .setView(input)
             .setPositiveButton("OK") { _, _ ->
                 if (verifyPin(input.text.toString())) {
+                    analytics.logAdminAccess(success = true)
                     setupUI()
                 } else {
+                    analytics.logAdminAccess(success = false)
                     Toast.makeText(this, "Invalid PIN", Toast.LENGTH_SHORT).show()
                     finish()
                 }

app/src/main/kotlin/farm/hobbs/kioskbrowser/MainActivity.kt

@@ -23,6 +23,7 @@ import android.widget.Toast
 import androidx.appcompat.app.AppCompatActivity
 import androidx.datastore.preferences.core.stringPreferencesKey
 import androidx.datastore.preferences.preferencesDataStore
+import farm.hobbs.kioskbrowser.analytics.AnalyticsManager
 import farm.hobbs.kioskbrowser.databinding.ActivityMainBinding
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.runBlocking
@@ -33,13 +34,16 @@ class MainActivity : AppCompatActivity() {
 
     private lateinit var binding: ActivityMainBinding
     private lateinit var webView: WebView
+    private lateinit var analytics: AnalyticsManager
     
     private val idleHandler = Handler(Looper.getMainLooper())
     private var idleTimeoutMs = 300_000L // 5 minutes default
     private var homepage = "https://hobbs.farm"
     private var whitelist = listOf("hobbs.farm")
+    private var sessionStartTime = 0L
     
     private val idleRunnable = Runnable {
+        analytics.logIdleReset()
         loadHomepage()
         clearSession()
     }
@@ -50,6 +54,11 @@ class MainActivity : AppCompatActivity() {
         binding = ActivityMainBinding.inflate(layoutInflater)
         setContentView(binding.root)
         
+        // Initialize analytics
+        analytics = AnalyticsManager.getInstance(this)
+        sessionStartTime = System.currentTimeMillis()
+        analytics.logSessionStart()
+        
         setupFullscreen()
         loadSettings()
         setupWebView()
@@ -121,6 +130,7 @@ class MainActivity : AppCompatActivity() {
             override fun onPageFinished(view: WebView?, url: String?) {
                 super.onPageFinished(view, url)
                 resetIdleTimer()
+                url?.let { analytics.logPageView(it) }
             }
         }
 
@@ -182,6 +192,12 @@ class MainActivity : AppCompatActivity() {
         super.onPause()
         idleHandler.removeCallbacks(idleRunnable)
     }
+    
+    override fun onDestroy() {
+        super.onDestroy()
+        val durationMs = System.currentTimeMillis() - sessionStartTime
+        analytics.logSessionEnd("app_close", durationMs)
+    }
 
     // Secret admin gesture: triple-tap top-left corner to open settings
     private var tapCount = 0