feat(chat): M4 思维链卡片 + 工具卡 + 图片

thinking.*/tool_call.*/tool_execution.update 累积进流式状态并渲染为可折叠卡片（思维链默认展开）；历史消息的 thinking（来自 REST /messages）同样展示；image 用 Coil 3 加载。

gradle/libs.versions.toml

@@ -13,6 +13,7 @@ coroutines = "1.11.0"
 securityCrypto = "1.1.0"
 junit = "4.13.2"
 datastore = "1.2.1"
+coil = "3.6.2"
 
 [libraries]
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
@@ -40,6 +41,8 @@ kotlinx-serialization-json = { group = "org.jetbrains.kotlinx", name = "kotlinx-
 kotlinx-coroutines-android = { group = "org.jetbrains.kotlinx", name = "kotlinx-coroutines-android", version.ref = "coroutines" }
 androidx-security-crypto = { group = "androidx.security", name = "security-crypto", version.ref = "securityCrypto" }
 androidx-datastore-preferences = { group = "androidx.datastore", name = "datastore-preferences", version.ref = "datastore" }
+coil-compose = { group = "io.coil-kt.coil3", name = "coil-compose", version.ref = "coil" }
+coil-network-okhttp = { group = "io.coil-kt.coil3", name = "coil-network-okhttp", version.ref = "coil" }
 junit = { group = "junit", name = "junit", version.ref = "junit" }
 
 [plugins]