feat(dao): tap-to-explain tooltip on the APC label

android/app/src/main/java/com/rjnr/pocketnode/ui/screens/dao/DaoScreen.kt

@@ -377,10 +377,10 @@ private fun DaoOverviewCard(
 
             Spacer(modifier = Modifier.height(4.dp))
 
-            Text(
-                text = "APC ~${String.format("%.2f", overview.currentApc)}%",
+            com.rjnr.pocketnode.ui.screens.dao.components.ApcLabel(
+                apc = overview.currentApc,
                 style = MaterialTheme.typography.bodySmall,
-                color = MaterialTheme.colorScheme.onSurfaceVariant
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
             )
 
             Spacer(modifier = Modifier.height(8.dp))

android/app/src/main/java/com/rjnr/pocketnode/ui/screens/dao/components/ApcLabel.kt

@@ -0,0 +1,94 @@
+package com.rjnr.pocketnode.ui.screens.dao.components
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.size
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.style.TextDecoration
+import androidx.compose.ui.unit.dp
+import com.composables.icons.lucide.Info
+import com.composables.icons.lucide.Lucide
+
+/**
+ * APC label with a tap-to-explain affordance. Reused by both the DAO
+ * overview header and the per-deposit cards so the explanation lives
+ * in one place.
+ *
+ * Why a tooltip exists: Pocket Node shows *realized* APC (the actual
+ * compensation accrued on this specific deposit divided by elapsed
+ * time), while the Neuron desktop wallet shows *theoretical* APC (a
+ * forward-looking projection from CKB tokenomics). Users who compare
+ * the two numbers will see different values and reasonably assume one
+ * is wrong. The tooltip explains the difference so the user can act
+ * on the right mental model.
+ */
+@Composable
+fun ApcLabel(
+    apc: Double,
+    style: androidx.compose.ui.text.TextStyle = MaterialTheme.typography.bodySmall,
+    color: androidx.compose.ui.graphics.Color = MaterialTheme.colorScheme.onSurfaceVariant,
+    prefix: String = "APC",
+    modifier: Modifier = Modifier,
+) {
+    var showInfo by remember { mutableStateOf(false) }
+
+    Row(
+        modifier = modifier.clickable { showInfo = true },
+        verticalAlignment = Alignment.CenterVertically,
+        horizontalArrangement = Arrangement.spacedBy(4.dp),
+    ) {
+        Text(
+            text = "$prefix ~${"%.2f".format(apc)}%",
+            style = style,
+            color = color,
+            textDecoration = TextDecoration.Underline,
+        )
+        Icon(
+            imageVector = Lucide.Info,
+            contentDescription = "What is APC?",
+            tint = color,
+            modifier = Modifier.size(12.dp),
+        )
+    }
+
+    if (showInfo) {
+        AlertDialog(
+            onDismissRequest = { showInfo = false },
+            title = { Text("About this APC") },
+            text = {
+                Text(
+                    text = "This number is the realized annual compensation rate: " +
+                        "the actual CKB earned on this deposit divided by the time " +
+                        "it has been deposited.\n\n" +
+                        "It may differ from the APC shown by other CKB wallets such " +
+                        "as Neuron. Neuron displays a theoretical APC computed from " +
+                        "the protocol's tokenomics — a forward-looking projection " +
+                        "assuming idealised conditions. Realized APC tracks what " +
+                        "your specific deposit has earned, which fluctuates with " +
+                        "actual on-chain participation.\n\n" +
+                        "Both numbers are valid. The realized number is the truth " +
+                        "about your deposit; the theoretical number is an estimate " +
+                        "of what a new deposit might earn.",
+                    style = MaterialTheme.typography.bodyMedium,
+                )
+            },
+            confirmButton = {
+                TextButton(onClick = { showInfo = false }) {
+                    Text("Got it")
+                }
+            },
+        )
+    }
+}

android/app/src/main/java/com/rjnr/pocketnode/ui/screens/dao/components/DaoDepositCard.kt

@@ -55,10 +55,10 @@ fun DaoDepositCard(
                     )
                     if (deposit.apc > 0.0) {
                         Spacer(modifier = Modifier.width(8.dp))
-                        Text(
-                            text = "APC \u2248 ${"%.2f".format(deposit.apc)}%",
+                        ApcLabel(
+                            apc = deposit.apc,
                             style = MaterialTheme.typography.bodySmall,
-                            color = MaterialTheme.colorScheme.onSurfaceVariant
+                            color = MaterialTheme.colorScheme.onSurfaceVariant,
                         )
                     }
                 }