refactor(privacy): drop I2pType.INTERNAL — EXTERNAL is the permanent answer

Earlier commits kept I2pType.INTERNAL as a placeholder for a follow-up
embedded daemon. We're not shipping that: I2P bootstrap on Android is
structurally minutes-long (no equivalent of Tor's hardcoded directory
authorities — NetDB peer discovery is protocol-inherent), so an embedded
router would mean a permanently-warming UX. Users who want I2P run i2pd /
Java I2P independently and point Amethyst at its SOCKS port.

Changes:
- commons I2pType drops the INTERNAL variant; parseI2pType collapses unknown
  codes to OFF
- I2pManager loses its INTERNAL switch arm
- I2pSettingsDialog drops the "treat INTERNAL as OFF" mapping it used to
  carry — the enum no longer has the case
- Android UI I2pSettings.resourceId drops the i2p_internal branch
- strings.xml drops the now-unused i2p_internal string
- I2pSharedPreferences hardens load: a stored "INTERNAL" from an earlier
  branch is no longer a valid I2pType, so runCatching swallows the
  IllegalArgumentException and the user lands on OFF
- PrivacyRouterTest fixtures use I2pType.EXTERNAL throughout

amethyst/src/main/java/com/vitorpamplona/amethyst/model/preferences/I2pSharedPreferences.kt

@@ -83,7 +83,13 @@ class I2pSharedPreferences(
             try {
                 val preferences = context.sharedPreferencesDataStore.data.first()
                 I2pSettings(
-                    i2pType = preferences[I2P_TYPE_KEY]?.let { I2pType.valueOf(it) } ?: I2pType.OFF,
+                    // A stored "INTERNAL" from an earlier branch is no longer a valid I2pType —
+                    // runCatching swallows the IllegalArgumentException so the user lands on OFF
+                    // and can re-enable EXTERNAL from the settings screen.
+                    i2pType =
+                        preferences[I2P_TYPE_KEY]
+                            ?.let { runCatching { I2pType.valueOf(it) }.getOrNull() }
+                            ?: I2pType.OFF,
                     externalSocksPort = preferences[EXTERNAL_SOCKS_PORT_KEY] ?: 4447,
                     i2pRelaysViaI2p = preferences[I2P_RELAYS_VIA_I2P_KEY] ?: true,
                     dmRelaysViaI2p = preferences[DM_RELAYS_VIA_I2P_KEY] ?: false,

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/i2p/I2pManager.kt

@@ -35,18 +35,16 @@ import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.stateIn
 
 /**
- * Mirror of TorManager, but EXTERNAL-only for now — no embedded I2P daemon ships
- * with this branch. When [I2pType.EXTERNAL] is selected, this manager surfaces the
- * configured SOCKS port; otherwise it emits [I2pServiceStatus.Off].
+ * EXTERNAL-only I2P manager. Mirrors TorManager's status surface but never starts
+ * a daemon itself: I2P bootstrap on Android is structurally minutes-long (no
+ * equivalent of Tor's hardcoded directory authorities — the protocol requires
+ * NetDB peer discovery), so the embedded route would ship a permanently-warming
+ * experience. Users who want I2P run i2pd / Java I2P independently and point
+ * Amethyst at its SOCKS port via the Privacy Options screen.
  *
  * There is intentionally no Connecting state, no bootstrap timeout, and no
- * "session bypass": with EXTERNAL the daemon's lifecycle is the user's
- * responsibility (i2pd / Java I2P running on the device), and the connection
- * either works or it doesn't — there's no in-app bootstrap to bypass.
- *
- * When INTERNAL is wired up in a follow-up, it will land here as a third branch
- * that starts an embedded daemon and emits Connecting / Active over its
- * lifecycle, mirroring the Tor flow.
+ * "session bypass" — when EXTERNAL is selected the daemon's lifecycle is the
+ * user's responsibility and the connection either works or it doesn't.
  */
 class I2pManager(
     i2pPrefs: I2pSharedPreferences,
@@ -59,8 +57,6 @@ class I2pManager(
         ) { type, port ->
             when (type) {
                 I2pType.OFF -> I2pServiceStatus.Off
-                // Persisted INTERNAL is treated as Off until an embedded daemon ships.
-                I2pType.INTERNAL -> I2pServiceStatus.Off
                 I2pType.EXTERNAL -> if (port > 0) I2pServiceStatus.Active(port) else I2pServiceStatus.Off
             }
         }.catch { e ->

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/i2p/I2pSettings.kt

@@ -28,6 +28,5 @@ val I2pType.resourceId: Int
     get() =
         when (this) {
             I2pType.OFF -> R.string.i2p_off
-            I2pType.INTERNAL -> R.string.i2p_internal
             I2pType.EXTERNAL -> R.string.i2p_external
         }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/i2p/I2pSettingsDialog.kt

@@ -49,13 +49,13 @@ import com.vitorpamplona.amethyst.ui.tor.SwitchSettingsRow
 import kotlinx.collections.immutable.persistentListOf
 
 // Settings body for I2P. Mirrors PrivacySettingsBody (Tor) but without presets —
-// no canonical "default I2P configuration" exists yet, and the per-feature toggles
+// no canonical "default I2P configuration" exists, and the per-feature toggles
 // only take effect when I2P is also the preferred clearnet transport (see the
 // global picker above this section in PrivacyOptionsScreen).
 //
-// INTERNAL is intentionally hidden from the picker until an embedded I2P daemon
-// ships. EXTERNAL connects to a user-run i2pd / Java I2P installation on the
-// device (default SOCKS port 4447).
+// I2P is EXTERNAL-only: connects to a user-run i2pd / Java I2P installation on
+// the device (default SOCKS port 4447). We intentionally do not embed a router —
+// see commons I2pType for the rationale.
 @Composable
 fun I2pSettingsBody(dialogViewModel: I2pDialogViewModel) {
     Column(
@@ -69,11 +69,8 @@ fun I2pSettingsBody(dialogViewModel: I2pDialogViewModel) {
                 TitleExplainer(stringRes(I2pType.OFF.resourceId)),
                 TitleExplainer(stringRes(I2pType.EXTERNAL.resourceId)),
             ),
-            // OFF screenCode is 0, EXTERNAL is 2. Spinner indices are 0/1.
-            // Map: dropdown index 0 → OFF, 1 → EXTERNAL.
             when (dialogViewModel.i2pType.value) {
                 I2pType.OFF -> 0
-                I2pType.INTERNAL -> 0 // Treat any persisted INTERNAL as OFF until daemon ships.
                 I2pType.EXTERNAL -> 1
             },
         ) { idx ->

amethyst/src/main/res/values/strings.xml

@@ -1103,7 +1103,6 @@
     <string name="use_i2p_explainer">Use an external I2P router (i2pd / Java I2P)</string>
 
     <string name="i2p_off">Off</string>
-    <string name="i2p_internal">Internal</string>
     <string name="i2p_external">External Router</string>
 
     <string name="i2p_socks_port">I2P Socks Port</string>

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/i2p/I2pSettings.kt

@@ -41,17 +41,20 @@ data class I2pSettings(
     val mediaUploadsViaI2p: Boolean = false,
 )
 
+// EXTERNAL-only: this app does not embed an I2P router. Bootstrap on Android is
+// minutes-long for a fresh netDb and the protocol provides no shortcut analogous
+// to Tor's hardcoded directory authorities; we'd ship a "permanently warming up"
+// experience. Users who want I2P run i2pd or Java I2P independently and point
+// Amethyst at its SOCKS port (default 4447). See I2pManager.
 enum class I2pType(
     val screenCode: Int,
 ) {
     OFF(0),
-    INTERNAL(1),
     EXTERNAL(2),
 }
 
 fun parseI2pType(code: Int?): I2pType =
     when (code) {
-        I2pType.INTERNAL.screenCode -> I2pType.INTERNAL
         I2pType.EXTERNAL.screenCode -> I2pType.EXTERNAL
         else -> I2pType.OFF
     }

commons/src/commonTest/kotlin/com/vitorpamplona/amethyst/commons/privacy/PrivacyRouterTest.kt

@@ -38,7 +38,7 @@ class PrivacyRouterTest {
         i2pOn: Boolean = false,
         preferred: PrivacyTransport = PrivacyTransport.DIRECT,
         tor: TorSettings = TorSettings(torType = if (torOn) TorType.INTERNAL else TorType.OFF),
-        i2p: I2pSettings = I2pSettings(i2pType = if (i2pOn) I2pType.INTERNAL else I2pType.OFF),
+        i2p: I2pSettings = I2pSettings(i2pType = if (i2pOn) I2pType.EXTERNAL else I2pType.OFF),
     ) = PrivacySettings(
         tor = tor,
         i2p = i2p,
@@ -125,7 +125,7 @@ class PrivacyRouterTest {
             settings(
                 i2pOn = true,
                 preferred = PrivacyTransport.I2P,
-                i2p = I2pSettings(i2pType = I2pType.INTERNAL, videosViaI2p = true),
+                i2p = I2pSettings(i2pType = I2pType.EXTERNAL, videosViaI2p = true),
             )
         assertEquals(PrivacyRoute.I2p, PrivacyRouter.route(clearnet, FeatureRole.VIDEO, s))
     }
@@ -136,7 +136,7 @@ class PrivacyRouterTest {
             settings(
                 i2pOn = true,
                 preferred = PrivacyTransport.I2P,
-                i2p = I2pSettings(i2pType = I2pType.INTERNAL, videosViaI2p = false),
+                i2p = I2pSettings(i2pType = I2pType.EXTERNAL, videosViaI2p = false),
             )
         assertEquals(PrivacyRoute.Direct, PrivacyRouter.route(clearnet, FeatureRole.VIDEO, s))
     }
@@ -162,7 +162,7 @@ class PrivacyRouterTest {
                 torOn = false,
                 i2pOn = true,
                 preferred = PrivacyTransport.TOR,
-                i2p = I2pSettings(i2pType = I2pType.INTERNAL, imagesViaI2p = true),
+                i2p = I2pSettings(i2pType = I2pType.EXTERNAL, imagesViaI2p = true),
             )
         assertEquals(PrivacyRoute.Direct, PrivacyRouter.route(clearnet, FeatureRole.IMAGE, s))
     }
@@ -176,7 +176,7 @@ class PrivacyRouterTest {
                 i2pOn = true,
                 preferred = PrivacyTransport.I2P,
                 tor = TorSettings(torType = TorType.INTERNAL, imagesViaTor = true),
-                i2p = I2pSettings(i2pType = I2pType.INTERNAL, imagesViaI2p = true),
+                i2p = I2pSettings(i2pType = I2pType.EXTERNAL, imagesViaI2p = true),
             )
         assertEquals(PrivacyRoute.I2p, PrivacyRouter.route(clearnet, FeatureRole.IMAGE, s))
     }