test(coverage): raise unit coverage past the 50% gate (phases 0-2)

Executes COVERAGE_PLAN.md phases 0-2 to clear the SonarQube new-code coverage
gate (was 16.4%, threshold 50%). Estimated new-code coverage after this change
is ~57%. 109 new tests across 19 files; full suite is 264 tests, all green.

Phase 0 — coverage exclusions (sonar-project.properties): drop code a JVM unit
test can't execute from the *coverage* denominator (still analysed for
bugs/smells) — pure-@Composable UI the `*Screen.kt` glob missed
(ui/components/**, BlockRenderer, ShardComponents), Android-framework glue
(push services, Keystore-backed Encrypted* stores, Hilt di/**).

Phase 1 — DTO serialization tests: AdminDto, PublicDto, WikiDto, PostDto/PageDto/
ContactDto, SsoDto, the shard board DTOs and player game-data DTOs, and the
mobile-auth request bodies — decode + encode + computed helpers
(isPublished/isMaintenance/ActorDto.label/ShardStatusDto.isOnline).

Phase 2 — ViewModel tests: a MainDispatcherRule harness + hand-written API fakes
(FakePublicApi/FakeAdminApi/FakePlayerShardApi/FakeShardStream) drive real
repositories into the ViewModels. Covers the admin (dashboard/content/moderation/
support), content (news/post/page/wiki/home/contact), player (characters/
vendors/character/my-houses) and shard-board (champs/guilds/governors/houses/
hub) ViewModels — load success/error, form validation, role/status-aware
feedback, and live-frame merging.

To make the shard boards testable, extract a small `ShardStream` interface from
`ShardStreamClient` (bound in NetworkModule) so `ShardRepository` depends on the
capability, not the OkHttp client — lets a fake stream replace the perpetual SSE
reconnect loop in tests. No production behaviour change.

Phases 3 (repositories) and 4 (core net/auth top-up) are follow-ups; the
deep-dependency auth family (Login/Account/TrustedDevices ViewModels,
AuthRepository) lands with them. See docs/android/COVERAGE_PLAN.md.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NgyHnrNa8WwG3doxvxjuCr

app/src/main/java/com/runicgateway/app/core/net/ShardStream.kt

@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.core.net
+
+import kotlinx.coroutines.flow.Flow
+
+/**
+ * The live shard SSE feed as a cold flow of lifecycle + frame events (PLAN.md §6.2,
+ * §7). Extracted as an interface so consumers (e.g. [com.runicgateway.app.data.repository.ShardRepository])
+ * depend on the capability, not the OkHttp-backed [ShardStreamClient] — the boards
+ * can then be unit-tested against a fake stream instead of a real network connection.
+ */
+interface ShardStream {
+    fun events(): Flow<ShardStreamEvent>
+}

app/src/main/java/com/runicgateway/app/core/net/ShardStreamClient.kt

@@ -40,7 +40,7 @@ class ShardStreamClient @Inject constructor(
     baseClient: OkHttpClient,
     private val baseUrlHolder: BaseUrlHolder,
     private val json: Json,
-) {
+) : ShardStream {
     // SSE is a long-lived, mostly-idle connection (keepalive comments every ~25s),
     // so the read timeout must be disabled or the idle stream would be killed.
     private val sseClient: OkHttpClient = baseClient.newBuilder()
@@ -56,7 +56,7 @@ class ShardStreamClient @Inject constructor(
      * drive a live/offline indicator; [ShardStreamEvent.Frame] carries a decoded
      * `{ kind, … }` payload the boards merge in place.
      */
-    fun events(): Flow<ShardStreamEvent> = channelFlow {
+    override fun events(): Flow<ShardStreamEvent> = channelFlow {
         var backoffMs = INITIAL_BACKOFF_MS
         while (isActive) {
             val url = baseUrlHolder.current?.resolve(STREAM_PATH)

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

@@ -3,7 +3,7 @@
  */
 package com.runicgateway.app.data.repository
 
-import com.runicgateway.app.core.net.ShardStreamClient
+import com.runicgateway.app.core.net.ShardStream
 import com.runicgateway.app.core.net.ShardStreamEvent
 import com.runicgateway.app.core.result.ApiResult
 import com.runicgateway.app.core.result.safeApiCall
@@ -35,7 +35,7 @@ import javax.inject.Singleton
 @Singleton
 class ShardRepository @Inject constructor(
     private val api: PublicApi,
-    private val stream: ShardStreamClient,
+    private val stream: ShardStream,
     private val json: Json,
 ) {
     // ── Snapshots ────────────────────────────────────────────────────────

app/src/main/java/com/runicgateway/app/di/NetworkModule.kt

@@ -9,6 +9,8 @@ import com.runicgateway.app.BuildConfig
 import com.runicgateway.app.core.net.AuthInterceptor
 import com.runicgateway.app.core.net.BaseUrlHolder
 import com.runicgateway.app.core.net.HostSelectionInterceptor
+import com.runicgateway.app.core.net.ShardStream
+import com.runicgateway.app.core.net.ShardStreamClient
 import com.runicgateway.app.core.net.TokenAuthenticator
 import com.runicgateway.app.core.net.UserAgentInterceptor
 import com.runicgateway.app.data.api.AuthApi
@@ -94,6 +96,12 @@ object NetworkModule {
     @Singleton
     fun providePublicApi(retrofit: Retrofit): PublicApi = retrofit.create(PublicApi::class.java)
 
+    /** Expose the live SSE feed as the [ShardStream] capability so repositories depend
+     *  on the interface (unit-testable against a fake), not the OkHttp-backed client. */
+    @Provides
+    @Singleton
+    fun provideShardStream(client: ShardStreamClient): ShardStream = client
+
     @Provides
     @Singleton
     fun provideAuthApi(retrofit: Retrofit): AuthApi = retrofit.create(AuthApi::class.java)