fix: 修复 Liblib provider 认证和多个图片生成关键缺陷

- 重写 LiblibImageProvider：Bearer token 改为 HMAC-SHA1 签名认证，
  适配 Liblib 真实 API（Star-3 Alpha 文生图端点）
- 修复 chapter.images JSON 列原地修改不持久化（深拷贝+整列重赋值）
- 修复 generate_chapter_images 在事务提交前派发（改为 commit 后统一 delay）
- 修复 initialize_chapter_images 覆盖已完成图片（新增 merge 去重逻辑）
- 修复 Android failed 图片渲染为错误卡片（改为隐藏，保持正文连续）
- 模型模板 UUID 改为环境变量配置（LIBLIB_TEMPLATE_UUID）
- 更新 .env 凭证格式为 ACCESS_KEY/SECRET_KEY
- 补充 test_memoir_image_bootstrap 缺失的 unittest.mock 导入

Made-with: Cursor

app-android/app/src/androidTest/java/com/huaga/life_echo/ui/components/memoir/ChapterReadingImageBlocksTest.kt

@@ -1,6 +1,7 @@
 package com.huaga.life_echo.ui.components.memoir
 
 import androidx.activity.ComponentActivity
+import androidx.compose.ui.test.assertDoesNotExist
 import androidx.compose.ui.test.assertIsDisplayed
 import androidx.compose.ui.test.junit4.createAndroidComposeRule
 import androidx.compose.ui.test.onNodeWithTag
@@ -50,7 +51,7 @@ class ChapterReadingImageBlocksTest {
     }
 
     @Test
-    fun chapterReadingView_showsFailureCard_forFailedImage_withoutRawPlaceholderText() {
+    fun chapterReadingView_hidesFailedImageBlock() {
         val chapter = ChapterContentDto(
             id = "chapter-1",
             title = "童年的夏天",
@@ -81,6 +82,6 @@ class ChapterReadingImageBlocksTest {
 
         composeRule.setContent { ChapterReadingView(chapter = chapter) }
 
-        composeRule.onNodeWithTag("memoir-image-error-0").assertIsDisplayed()
+        composeRule.onNodeWithTag("memoir-image-error-0").assertDoesNotExist()
     }
 }

app-android/app/src/main/java/com/huaga/life_echo/ui/components/memoir/MemoirContentBlocks.kt

@@ -24,7 +24,7 @@ fun splitMemoirContent(content: String, images: List<ChapterImageDto>): List<Mem
         if (before.isNotBlank()) blocks += MemoirContentBlock.Text(before)
         if (image.status == "completed" && !image.url.isNullOrBlank()) {
             blocks += MemoirContentBlock.Image(image)
-        } else if (image.status in listOf("pending", "processing", "failed")) {
+        } else if (image.status == "pending" || image.status == "processing") {
             blocks += MemoirContentBlock.Image(image)
         }
         remaining = parts.getOrElse(1) { "" }

app-android/app/src/main/java/com/huaga/life_echo/ui/components/memoir/MemoirInlineImage.kt

@@ -8,10 +8,8 @@ import androidx.compose.animation.core.tween
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
-import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
@@ -21,7 +19,6 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.layout.ContentScale
 import androidx.compose.ui.platform.testTag
-import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import coil.compose.AsyncImage
 import com.huaga.life_echo.network.models.ChapterImageDto
@@ -73,29 +70,6 @@ fun MemoirInlineImage(
                 )
             }
         }
-        "failed" -> Column(
-            modifier = modifier
-                .fillMaxWidth()
-                .clip(RoundedCornerShape(16.dp))
-                .background(LightPurple.copy(alpha = 0.10f))
-                .padding(16.dp)
-                .testTag("memoir-image-error-${image.index}")
-        ) {
-            Text(
-                text = "图片生成失败",
-                fontSize = AppTypography.bodyMedium,
-                fontWeight = FontWeight.Medium,
-                color = SlatePurple,
-            )
-            if (image.description.isNotBlank()) {
-                Text(
-                    text = image.description,
-                    fontSize = AppTypography.captionMedium,
-                    color = SlatePurple.copy(alpha = 0.6f),
-                    modifier = Modifier.padding(top = 4.dp),
-                )
-            }
-        }
         else -> Unit
     }
 }

app-android/app/src/test/java/com/huaga/life_echo/ui/components/memoir/MemoirContentBlocksTest.kt

@@ -2,6 +2,7 @@ package com.huaga.life_echo.ui.components.memoir
 
 import com.huaga.life_echo.network.models.ChapterImageDto
 import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
 import org.junit.Assert.assertTrue
 import org.junit.Test
 
@@ -56,4 +57,33 @@ class MemoirContentBlocksTest {
         val text = (blocks[0] as MemoirContentBlock.Text).content
         assertTrue(!text.contains("IMAGE:"))
     }
+
+    @Test
+    fun splitMemoirContent_skipsFailedImages_andRemovesTheirPlaceholders() {
+        val blocks = splitMemoirContent(
+            content = "开头。\n\n{{{{IMAGE:生成失败的图}}}}\n\n结尾。",
+            images = listOf(
+                ChapterImageDto(
+                    index = 0,
+                    placeholder = "{{{{IMAGE:生成失败的图}}}}",
+                    description = "生成失败的图",
+                    prompt = null,
+                    url = null,
+                    status = "failed",
+                    provider = "liblib",
+                    style = "watercolor",
+                    size = "1024x1024",
+                    error = "provider timeout",
+                    created_at = null,
+                    updated_at = null,
+                )
+            )
+        )
+
+        assertFalse(blocks.any { it is MemoirContentBlock.Image })
+        val combinedText = blocks.filterIsInstance<MemoirContentBlock.Text>().joinToString("\n") { it.content }
+        assertFalse(combinedText.contains("IMAGE:"))
+        assertTrue(combinedText.contains("开头"))
+        assertTrue(combinedText.contains("结尾"))
+    }
 }