feat(chat): remove legacy bubble renderer, full-bleed is the only chat style (#881)

Deletes the ChatMessageList/ChatStreaming bubble path and the ChatStyle
setting (issue #866 phase 6). ChatScreen now renders FullBleedChatList
directly; ChatBubble becomes the user-message anchor with the shared
SystemBubble/InlineAttachment/formatTimestamp helpers intact. Stubs of
AuthManager.getChatStyle() removed from four test suites; TodoTaskCardTest
renders ToolBubble directly.

Verified: ktlintCheck green, testDebugUnitTest 962/962 pass, assembleDebug
APK builds.

Co-authored-by: M57 <hy4ri@users.noreply.github.com>

app/src/main/java/com/m57/hermescontrol/ui/settings/SettingsSubPages.kt

@@ -163,8 +163,6 @@ internal fun SettingsChatPage(
                 onTypingEffectEnabledChange = viewModel::onTypingEffectEnabledChange,
                 typingEffectDelayMs = state.typingEffectDelayMs,
                 onTypingEffectDelayMsChange = viewModel::onTypingEffectDelayMsChange,
-                chatStyle = state.chatStyle,
-                onChatStyleChange = viewModel::onChatStyleChange,
             )
         }
     }

app/src/main/java/com/m57/hermescontrol/ui/settings/SettingsViewModel.kt

@@ -11,7 +11,6 @@ import com.m57.hermescontrol.data.remote.NetworkResult
 import com.m57.hermescontrol.data.remote.ServerEndpoint
 import com.m57.hermescontrol.data.remote.safeApiCall
 import com.m57.hermescontrol.data.ws.HermesWsClient
-import com.m57.hermescontrol.theme.ChatStyle
 import com.m57.hermescontrol.theme.ThemePreference
 import com.m57.hermescontrol.theme.ThemePreset
 import kotlinx.coroutines.CoroutineDispatcher
@@ -36,7 +35,6 @@ data class SettingsUiState(
     val isSaved: Boolean = false,
     val typingEffectEnabled: Boolean = false,
     val typingEffectDelayMs: Int = 30,
-    val chatStyle: ChatStyle = ChatStyle.FULL_BLEED,
     val profiles: List<ConnectionProfile> = emptyList(),
     val selectedProfileId: String? = null,
     val renameProfileName: String = "",
@@ -77,7 +75,6 @@ class SettingsViewModel(
         val themePreset = AuthManager.getThemePreset()
         val typingEffectEnabled = AuthManager.isTypingEffectEnabled()
         val typingEffectDelayMs = AuthManager.getTypingEffectDelayMs()
-        val chatStyle = AuthManager.getChatStyle()
         val profiles = AuthManager.getConnectionProfiles()
         val appLanguage = AuthManager.getAppLanguage()
         val renameProfileName =
@@ -97,7 +94,6 @@ class SettingsViewModel(
                 themePreset = themePreset,
                 typingEffectEnabled = typingEffectEnabled,
                 typingEffectDelayMs = typingEffectDelayMs,
-                chatStyle = chatStyle,
                 profiles = profiles,
                 selectedProfileId = selectedId,
                 renameProfileName = renameProfileName,
@@ -298,11 +294,6 @@ class SettingsViewModel(
         AuthManager.setTypingEffectDelayMs(delayMs)
     }
 
-    fun onChatStyleChange(style: ChatStyle) {
-        _uiState.update { it.copy(chatStyle = style, isSaved = false) }
-        AuthManager.setChatStyle(style)
-    }
-
     /** Clear all auth credentials — logs out and returns to landing screen. */
     fun logout() {
         AuthManager.setToken(null)
@@ -329,7 +320,6 @@ class SettingsViewModel(
         AuthManager.setThemePreset(state.themePreset)
         AuthManager.setTypingEffectEnabled(state.typingEffectEnabled)
         AuthManager.setTypingEffectDelayMs(state.typingEffectDelayMs)
-        AuthManager.setChatStyle(state.chatStyle)
         ApiClient.rebuild()
 
         viewModelScope.launch(ioDispatcher) {

app/src/main/java/com/m57/hermescontrol/ui/settings/components/AppearanceSection.kt

@@ -32,7 +32,6 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import com.m57.hermescontrol.R
-import com.m57.hermescontrol.theme.ChatStyle
 import com.m57.hermescontrol.theme.ThemePreference
 import com.m57.hermescontrol.theme.ThemePreset
 import com.m57.hermescontrol.ui.settings.SectionCard
@@ -235,46 +234,8 @@ internal fun ChatSection(
     onTypingEffectEnabledChange: (Boolean) -> Unit,
     typingEffectDelayMs: Int,
     onTypingEffectDelayMsChange: (Int) -> Unit,
-    chatStyle: ChatStyle,
-    onChatStyleChange: (ChatStyle) -> Unit,
 ) {
     SectionCard {
-        // Chat rendering style (issue #866): bubble renderer (default) or the
-        // parallel full-bleed renderer. Kept at the top of the section — it's
-        // the primary chat-behavior choice.
-        Text(
-            text = stringResource(R.string.settings_item_chat_style),
-            style = MaterialTheme.typography.bodyLarge,
-        )
-        Text(
-            text = stringResource(R.string.settings_desc_chat_style),
-            style =
-                MaterialTheme.typography.bodySmall.copy(
-                    color = MaterialTheme.colorScheme.onSurfaceVariant,
-                ),
-        )
-        Spacer(modifier = Modifier.height(8.dp))
-        SingleChoiceSegmentedButtonRow(modifier = Modifier.fillMaxWidth()) {
-            ChatStyle.entries.forEachIndexed { index, style ->
-                SegmentedButton(
-                    selected = chatStyle == style,
-                    onClick = { onChatStyleChange(style) },
-                    shape =
-                        SegmentedButtonDefaults.itemShape(
-                            index = index,
-                            count = ChatStyle.entries.size,
-                        ),
-                ) {
-                    Text(
-                        when (style) {
-                            ChatStyle.BUBBLES -> stringResource(R.string.chat_style_bubbles)
-                            ChatStyle.FULL_BLEED -> stringResource(R.string.chat_style_full_bleed)
-                        },
-                    )
-                }
-            }
-        }
-
         Spacer(modifier = Modifier.height(16.dp))
 
         Row(