feat(android): 工单列表与动作，任务页可进工单

- Api 增 tickets/ticketAction/verifyTicket/promote，状态机交给服务端，客户端只发动作
- TicketsScreen：派给我的 / 我发起的、按状态给接收/开始/提交/通过/驳回、6004 与 6003 给出人话提示
- 仍未编译验证（本机无 JDK/Gradle），见 android/README.md

android/app/src/main/java/com/dadao/task/MainActivity.kt

@@ -20,6 +20,7 @@ import com.dadao.task.ui.DadaoTheme
 import com.dadao.task.ui.HomeScreen
 import com.dadao.task.ui.LoginScreen
 import com.dadao.task.ui.TaskListScreen
+import com.dadao.task.ui.TicketsScreen
 
 class MainActivity : ComponentActivity() {
 
@@ -35,7 +36,7 @@ class MainActivity : ComponentActivity() {
     }
 }
 
-private enum class Screen { Splash, Login, Home, Tasks }
+private enum class Screen { Splash, Login, Home, Tasks, Tickets }
 
 @Composable
 private fun AppRoot() {
@@ -77,7 +78,20 @@ private fun AppRoot() {
             if (ws == null) {
                 screen = Screen.Home
             } else {
-                TaskListScreen(api = api, workspace = ws, onBack = { screen = Screen.Home })
+                TaskListScreen(
+                    api = api,
+                    workspace = ws,
+                    onBack = { screen = Screen.Home },
+                    onOpenTickets = { screen = Screen.Tickets },
+                )
+            }
+        }
+        Screen.Tickets -> {
+            val ws = current
+            if (ws == null) {
+                screen = Screen.Home
+            } else {
+                TicketsScreen(api = api, workspace = ws, onBack = { screen = Screen.Tasks })
             }
         }
     }

android/app/src/main/java/com/dadao/task/data/Api.kt

@@ -129,6 +129,39 @@ data class Invitation(
     @SerialName("expires_at") val expiresAt: String,
 )
 
+/** 与 backend/app/models_ticket.py 的 `ticket_ext` 对齐（只取手机端要显示的）。 */
+@Serializable
+data class TicketInfo(
+    @SerialName("requester_id") val requesterId: String = "",
+    @SerialName("assignee_id") val assigneeId: String = "",
+    @SerialName("parent_item_id") val parentItemId: String? = null,
+    @SerialName("reject_count") val rejectCount: Int = 0,
+    @SerialName("resolution_md") val resolutionMd: String = "",
+)
+
+/**
+ * 工单 = 一条 kind=ticket 的 item + 一份 ticket 扩展。
+ * 结构上就是 [Item] 多一个 ticket 字段，所以不要另起一套字段名。
+ */
+@Serializable
+data class Ticket(
+    val id: String,
+    val title: String,
+    @SerialName("body_md") val bodyMd: String = "",
+    val status: String,
+    val priority: Int = 1,
+    @SerialName("due_at") val dueAt: String? = null,
+    @SerialName("version") val version: Int = 1,
+    val ticket: TicketInfo = TicketInfo(),
+)
+
+@Serializable
+data class TicketPage(
+    val tickets: List<Ticket> = emptyList(),
+    @SerialName("next_cursor") val nextCursor: String? = null,
+    @SerialName("has_more") val hasMore: Boolean = false,
+)
+
 private data class SmsRequest(val phone: String)
 private data class LoginRequest(val phone: String, val code: String)
 private data class RefreshRequest(@SerialName("refresh_token") val refreshToken: String)
@@ -219,6 +252,57 @@ class Api(private val tokens: TokenStore) {
         auth = true,
     )
 
+    // ---- M2 工单 ----
+
+    /** role: assigned（派给我的）/ requested（我发起的）/ all。 */
+    suspend fun tickets(workspaceId: String, role: String = "assigned"): TicketPage =
+        call(path = "/workspaces/$workspaceId/tickets?role=$role", auth = true)
+
+    /**
+     * 工单动作。状态机在服务端，这里只发"做什么"，不自己算目标状态——
+     * 客户端如果自己判断，规则一改就会和前端的按钮显隐对不上。
+     */
+    suspend fun ticketAction(
+        workspaceId: String,
+        itemId: String,
+        action: String,
+        body: Map<String, Any> = emptyMap(),
+    ): Ticket = call(
+        path = "/workspaces/$workspaceId/items/$itemId/ticket/$action",
+        body = json.encodeToString(body),
+        auth = true,
+    )
+
+    suspend fun verifyTicket(
+        workspaceId: String,
+        itemId: String,
+        approve: Boolean,
+        note: String = "",
+        resolution: String = "",
+    ): Ticket = ticketAction(
+        workspaceId,
+        itemId,
+        "verify",
+        mapOf("approve" to approve, "note" to note, "resolution_md" to resolution),
+    )
+
+    /** 把任务升级成工单：原任务留在原地变"被阻塞"，不搬数据。 */
+    suspend fun promote(
+        workspaceId: String,
+        itemId: String,
+        assigneeId: String,
+        version: Int? = null,
+    ): JsonElement = call(
+        path = "/workspaces/$workspaceId/items/$itemId/promote",
+        body = json.encodeToString(
+            buildMap {
+                put("assignee_id", assigneeId)
+                if (version != null) put("version", version)
+            },
+        ),
+        auth = true,
+    )
+
     private suspend inline fun <reified T> call(
         path: String,
         body: String? = null,

android/app/src/main/java/com/dadao/task/ui/TaskListScreen.kt

@@ -72,6 +72,7 @@ fun TaskListScreen(
     api: Api,
     workspace: Workspace,
     onBack: () -> Unit,
+    onOpenTickets: () -> Unit = {},
 ) {
     val items = remember { mutableStateListOf<Item>() }
     var view by remember { mutableStateOf("today") }
@@ -127,6 +128,7 @@ fun TaskListScreen(
             TopAppBar(
                 title = { Text(workspace.name) },
                 navigationIcon = { TextButton(onClick = onBack) { Text("返回") } },
+                actions = { TextButton(onClick = onOpenTickets) { Text("工单") } },
             )
         },
     ) { padding ->

android/app/src/main/java/com/dadao/task/ui/TicketsScreen.kt

@@ -0,0 +1,199 @@
+package com.dadao.task.ui
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material3.Card
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.FilterChip
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.material3.TopAppBar
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateListOf
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import com.dadao.task.data.Api
+import com.dadao.task.data.ApiException
+import com.dadao.task.data.Ticket
+import com.dadao.task.data.Workspace
+import kotlinx.coroutines.launch
+
+private val ROLES = listOf(
+    "assigned" to "派给我的",
+    "requested" to "我发起的",
+)
+
+private val TICKET_STATUS_LABEL = mapOf(
+    "open" to "待接收",
+    "accepted" to "待办理",
+    "in_progress" to "办理中",
+    "pending_verify" to "待验收",
+    "done" to "已完成",
+    "canceled" to "已取消",
+)
+
+/**
+ * 工单列表（移动端只做"该我办的"与"我发起的"两栏）。
+ *
+ * 为什么手机端也必须有：需要别人帮忙时，人往往不在电脑前。
+ * 只做查看不做动作的工单页等于把流程卡在桌面端，等于没有协同。
+ */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun TicketsScreen(
+    api: Api,
+    workspace: Workspace,
+    onBack: () -> Unit,
+) {
+    val tickets = remember { mutableStateListOf<Ticket>() }
+    var role by remember { mutableStateOf("assigned") }
+    var loading by remember { mutableStateOf(true) }
+    var error by remember { mutableStateOf<String?>(null) }
+    val scope = rememberCoroutineScope()
+
+    suspend fun reload() {
+        loading = true
+        error = null
+        try {
+            val page = api.tickets(workspace.id, role)
+            tickets.clear()
+            tickets.addAll(page.tickets)
+        } catch (e: ApiException) {
+            error = e.message
+        } finally {
+            loading = false
+        }
+    }
+
+    LaunchedEffect(role) { reload() }
+
+    suspend fun act(ticket: Ticket, action: String, approve: Boolean = false) {
+        try {
+            val updated = if (action == "verify") {
+                api.verifyTicket(workspace.id, ticket.id, approve)
+            } else {
+                api.ticketAction(workspace.id, ticket.id, action)
+            }
+            val index = tickets.indexOfFirst { it.id == updated.id }
+            if (index >= 0) tickets[index] = updated
+            // 办完就不该再占着"待我处理"的位置
+            if (updated.status == "done" && role == "assigned") tickets.removeAll { it.id == updated.id }
+        } catch (e: ApiException) {
+            error = when (e.code) {
+                6004 -> "这个动作得由需求人来点（自己不能验收自己的工单）"
+                6003 -> "当前状态不允许这个操作，可能刚被别人推进了一步"
+                else -> e.message
+            }
+            reload()
+        }
+    }
+
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = { Text("${workspace.name} · 工单") },
+                navigationIcon = { TextButton(onClick = onBack) { Text("返回") } },
+            )
+        },
+    ) { padding ->
+        Column(Modifier.fillMaxSize().padding(padding).padding(horizontal = 16.dp)) {
+            Row(
+                Modifier.fillMaxWidth().padding(vertical = 8.dp),
+                horizontalArrangement = Arrangement.spacedBy(8.dp),
+            ) {
+                ROLES.forEach { (key, label) ->
+                    FilterChip(
+                        selected = role == key,
+                        onClick = { role = key },
+                        label = { Text(label) },
+                    )
+                }
+            }
+
+            error?.let {
+                Spacer(Modifier.height(8.dp))
+                Text(it, color = MaterialTheme.colorScheme.error, style = MaterialTheme.typography.bodySmall)
+            }
+
+            when {
+                loading -> Text("加载中…")
+                tickets.isEmpty() -> Text(
+                    if (role == "assigned") "没有需要你出手的事。" else "你还没找人帮过忙。",
+                    style = MaterialTheme.typography.bodyMedium,
+                )
+                else -> LazyColumn(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+                    items(tickets, key = { it.id }) { ticket ->
+                        Card(Modifier.fillMaxWidth()) {
+                            Column(Modifier.fillMaxWidth().padding(12.dp)) {
+                                Text(ticket.title, style = MaterialTheme.typography.titleMedium)
+                                Spacer(Modifier.height(4.dp))
+                                Text(
+                                    buildString {
+                                        append(TICKET_STATUS_LABEL[ticket.status] ?: ticket.status)
+                                        if (ticket.ticket.rejectCount > 0) {
+                                            append(" · 已退回 ").append(ticket.ticket.rejectCount).append(" 次")
+                                        }
+                                    },
+                                    style = MaterialTheme.typography.bodySmall,
+                                )
+                                Row(
+                                    Modifier.fillMaxWidth().padding(top = 4.dp),
+                                    verticalAlignment = Alignment.CenterVertically,
+                                ) {
+                                    when (ticket.status) {
+                                        "open" -> ActionButton("接收") {
+                                            scope.launch { act(ticket, "accept") }
+                                        }
+                                        "accepted" -> ActionButton("开始") {
+                                            scope.launch { act(ticket, "start") }
+                                        }
+                                        "in_progress" -> ActionButton("提交验收") {
+                                            scope.launch { act(ticket, "submit") }
+                                        }
+                                        "pending_verify" -> {
+                                            ActionButton("通过") {
+                                                scope.launch { act(ticket, "verify", approve = true) }
+                                            }
+                                            ActionButton("驳回") {
+                                                scope.launch { act(ticket, "verify", approve = false) }
+                                            }
+                                        }
+                                        else -> Unit
+                                    }
+                                    Spacer(Modifier.weight(1f))
+                                    if (ticket.status != "done" && ticket.status != "canceled") {
+                                        TextButton(onClick = { scope.launch { act(ticket, "cancel") } }) {
+                                            Text("取消")
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun ActionButton(label: String, onClick: () -> Unit) {
+    TextButton(onClick = onClick) { Text(label) }
+}