feat(namecoin): mention umbrel alongside StartOS in docs and UI hints

Both umbrelOS (via getumbrel/umbrel-apps#4962) and StartOS / Start9
(via Start9-Community/namecoin-core-startos) ship a self-hosted
Namecoin Core that this backend can target. Generalize the
help/strings so umbrel users discover the feature too.

No logic changes.

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/settings/NamecoinSettingsSection.kt

@@ -912,8 +912,9 @@ private fun NamecoinCoreRpcSection(
         Spacer(Modifier.height(4.dp))
         Text(
             "URL, username and password for your Namecoin Core node. " +
-                "StartOS users: copy these from the package's Properties tab " +
-                "(Tor onion URL recommended for remote access).",
+                "StartOS / Start9 users: copy these from the package's Properties tab. " +
+                "Umbrel users: see the Namecoin Core app's 'Connect From Outside' card. " +
+                "Tor onion URL recommended for remote access.",
             style = MaterialTheme.typography.bodySmall,
             color = MaterialTheme.colorScheme.onSurfaceVariant,
         )

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip05DnsIdentifiers/namecoin/NamecoinBackend.kt

@@ -47,9 +47,10 @@ enum class NamecoinBackend {
  *
  * The URL is expected to be the root of the RPC server (e.g.
  * `http://192.168.1.42:8336/`, `http://<onion>.onion:8336/`, or
- * `https://lan-host/` when StartOS terminates TLS for you). The user
- * supplies username and password; cookie-auth is not supported because
- * the user typically isn't running this on the same host as the node.
+ * `https://lan-host/` when StartOS or umbrel terminate TLS for you).
+ * The user supplies username and password; cookie-auth is not
+ * supported because the user typically isn't running this on the same
+ * host as the node.
  *
  * Tor onion endpoints are resolved through the same `socketFactoryForNip05`
  * path as the existing ElectrumX traffic, so they obey the user's Tor
@@ -57,7 +58,7 @@ enum class NamecoinBackend {
  *
  * `usePinnedTrustStore` mirrors the ElectrumX flag: set true to route
  * the HTTPS request through the pinned-cert socket factory (used for
- * StartOS LAN endpoints with self-signed root, etc.).
+ * StartOS / umbrel LAN endpoints with self-signed root, etc.).
  */
 @Serializable
 data class NamecoinCoreRpcConfig(
@@ -67,9 +68,9 @@ data class NamecoinCoreRpcConfig(
      * reverse proxy mounts the RPC under a sub-path).
      */
     val url: String = "",
-    /** RPC username (StartOS "RPC Credentials" → Username). */
+    /** RPC username (StartOS "RPC Credentials" → Username, umbrel 'Connect From Outside' → RPC User). */
     val username: String = "",
-    /** RPC password (StartOS "RPC Credentials" → Password). */
+    /** RPC password (StartOS "RPC Credentials" → Password, umbrel 'Connect From Outside' → RPC Password). */
     val password: String = "",
     /**
      * Per-call timeout in milliseconds. Defaults to 15 seconds, well
@@ -77,7 +78,7 @@ data class NamecoinCoreRpcConfig(
      * single slow node doesn't burn the whole budget.
      */
     val timeoutMs: Long = 15_000L,
-    /** Use the pinned trust store (self-signed StartOS LAN cert, etc.). */
+    /** Use the pinned trust store (self-signed StartOS / umbrel LAN cert, etc.). */
     val usePinnedTrustStore: Boolean = false,
 ) {
     val isUsable: Boolean

quartz/src/jvmAndroid/kotlin/com/vitorpamplona/quartz/nip05DnsIdentifiers/namecoin/NamecoinCoreRpcClient.kt

@@ -41,8 +41,8 @@ import java.util.concurrent.TimeUnit
  * Namecoin Core JSON-RPC client.
  *
  * Implements [NamecoinNameBackend] by issuing a `name_show` JSON-RPC call
- * against a user-configured Namecoin Core node — typically a StartOS
- * install reached over its Tor hidden service or LAN URL.
+ * against a user-configured Namecoin Core node — typically a StartOS or
+ * umbrel install reached over its Tor hidden service or LAN URL.
  *
  * The transport is delegated to an [OkHttpClient] supplied by the caller
  * (Amethyst plumbs it through `roleBasedHttpClientBuilder.okHttpClientForNip05(url)`