feat(account): several Steam accounts on the account screen

Steam sign-in (docs/website/STEAM_SIGNIN.md) lets a person link more than one
Steam account. Unlink went by provider, so it would have removed all of them;
it now sends the identity's id (DELETE …/identities/:provider?id=). A Steam row
reads "Steam: <persona name>" with its SteamID64 beneath, since Steam sends no
email. The sign-in sheet already lists providers from /auth/providers, so Steam
appears there with no change.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E14m6SuuY6i1vASFeGDBeY

app/src/main/java/com/runicgateway/app/data/api/MeApi.kt

@@ -27,6 +27,7 @@ import retrofit2.http.HTTP
 import retrofit2.http.PATCH
 import retrofit2.http.POST
 import retrofit2.http.Path
+import retrofit2.http.Query
 
 /**
  * The role-agnostic self-service surface (PLAN.md §6.3, §6.4): account, credential
@@ -60,8 +61,10 @@ interface MeApi {
 
     // DELETE with no body — a plain @DELETE would suffice, but @HTTP keeps the
     // path template explicit alongside the provider argument.
+    // `id` (optional) removes that one identity rather than every one of the
+    // provider — a person may link several Steam accounts (STEAM_SIGNIN.md).
     @HTTP(method = "DELETE", path = "api/v1/auth/me/account/identities/{provider}")
-    suspend fun unlinkIdentity(@Path("provider") provider: String): Unit
+    suspend fun unlinkIdentity(@Path("provider") provider: String, @Query("id") id: Int? = null): Unit
 
     // ── Trusted devices (TRUSTED_DEVICES_MFA.md) — devices allowed to skip TOTP ──
 

app/src/main/java/com/runicgateway/app/data/api/dto/AccountDto.kt

@@ -128,10 +128,18 @@ data class RecoveryGenerateRequest(val currentPassword: String? = null)
 @Serializable
 data class RecoveryCodesDto(val recoveryCodes: List<String> = emptyList())
 
-/** A linked external identity (`GET /auth/me/account/identities`). */
+/**
+ * A linked external identity (`GET /auth/me/account/identities`). [id] unlinks this
+ * one identity when a provider has several (a person may link more than one Steam
+ * account); [subject] is the person's own external id — for Steam the SteamID64 —
+ * and [display_name] the Steam persona name (null for other providers).
+ */
 @Serializable
 data class LinkedIdentityDto(
+    val id: Int? = null,
     val provider: String = "",
+    val subject: String? = null,
     val email: String? = null,
+    val display_name: String? = null,
     val linked_at: String? = null,
 )

app/src/main/java/com/runicgateway/app/data/api/dto/SsoDto.kt

@@ -16,7 +16,7 @@ import kotlinx.serialization.Serializable
 
 /**
  * One entry of `GET /auth/providers` — public discovery, never secrets. [icon] is
- * the provider kind (`google` | `discord` | `oidc` | `oauth2`); the app renders a
+ * the provider kind (`google` | `discord` | `steam` | `oidc` | `oauth2`); the app renders a
  * button per provider from this list rather than hardcoding a set. [loginUrl] is
  * the *website* start path (unused by the app, which builds its own
  * `/auth/mobile/sso/start` URL); kept so the shape matches the backend exactly.

app/src/main/java/com/runicgateway/app/data/repository/AccountRepository.kt

@@ -56,8 +56,8 @@ class AccountRepository @Inject constructor(
 
     suspend fun identities(): ApiResult<List<LinkedIdentityDto>> = safeApiCall { api.identities() }
 
-    suspend fun unlinkIdentity(provider: String): ApiResult<Unit> =
+    suspend fun unlinkIdentity(provider: String, id: Int? = null): ApiResult<Unit> =
-        safeApiCall { api.unlinkIdentity(provider) }
+        safeApiCall { api.unlinkIdentity(provider, id) }
 
     // ── Trusted devices (TRUSTED_DEVICES_MFA.md) ───────────────────────────
 

app/src/main/java/com/runicgateway/app/ui/auth/AccountScreen.kt

@@ -329,15 +329,18 @@ private fun IdentityRow(identity: LinkedIdentityDto, busy: Boolean, viewModel: A
         verticalAlignment = Alignment.CenterVertically,
     ) {
         Column(Modifier.weight(1f)) {
+            val provider = identity.provider.replaceFirstChar { it.uppercase() }
             Text(
-                identity.provider.replaceFirstChar { it.uppercase() },
+                // Steam: "Steam: CoolGuy99" — a person may hold several, so the name tells them apart.
+                identity.display_name?.let { stringResource(R.string.account_identity_named, provider, it) } ?: provider,
                 style = MaterialTheme.typography.bodyLarge,
             )
-            identity.email?.let {
+            // Steam sends no email; its SteamID64 identifies the account instead.
+            (identity.email ?: identity.subject?.takeIf { identity.provider == "steam" })?.let {
                 Text(it, style = MaterialTheme.typography.bodySmall, color = MaterialTheme.colorScheme.onSurfaceVariant)
             }
         }
-        TextButton(onClick = { viewModel.unlinkIdentity(identity.provider) }, enabled = !busy) {
+        TextButton(onClick = { viewModel.unlinkIdentity(identity) }, enabled = !busy) {
             Text(stringResource(R.string.account_identity_unlink))
         }
     }

app/src/main/java/com/runicgateway/app/ui/auth/AccountViewModel.kt

@@ -158,11 +158,12 @@ class AccountViewModel @Inject constructor(
     }
 
     // ── Identities ───────────────────────────────────────────────────────
-    fun unlinkIdentity(provider: String) {
+    /** Unlink [identity] alone — by its id, so one of several Steam accounts goes and the rest stay. */
+    fun unlinkIdentity(identity: LinkedIdentityDto) {
         if (_state.value.busy) return
         _state.update { it.copy(busy = true, feedback = null) }
         viewModelScope.launch {
-            when (accountRepository.unlinkIdentity(provider)) {
+            when (accountRepository.unlinkIdentity(identity.provider, identity.id)) {
                 is ApiResult.Ok -> {
                     finish(Section.IDENTITY, true, R.string.account_identity_unlinked)
                     when (val ids = accountRepository.identities()) {

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

@@ -208,6 +208,8 @@
     <string name="account_identities_title">Linked accounts</string>
     <string name="account_identities_empty">No linked sign-in providers.</string>
     <string name="account_identity_unlink">Unlink</string>
+    <!-- A provider that reports a name (Steam): "Steam: CoolGuy99". -->
+    <string name="account_identity_named">%1$s: %2$s</string>
     <string name="account_identity_unlinked">Account unlinked.</string>
     <string name="account_identity_error">Couldn\'t unlink that account.</string>
 

app/src/test/java/com/runicgateway/app/data/repository/AccountTrustedDevicesTest.kt

@@ -70,7 +70,7 @@ class AccountTrustedDevicesTest {
         override suspend fun totpEnable(body: TotpCodeRequest): TotpStateDto = TotpStateDto()
         override suspend fun totpDisable(body: TotpCodeRequest): TotpStateDto = TotpStateDto()
         override suspend fun identities(): List<LinkedIdentityDto> = emptyList()
-        override suspend fun unlinkIdentity(provider: String) = Unit
+        override suspend fun unlinkIdentity(provider: String, id: Int?) = Unit
     }
 
     private fun repo(api: MeApi) = AccountRepository(api, json)