feat: delete task/account, edit endpoint, richer event log

- store: DeleteAccount, DeleteTask, UpdateEndpoint (+ cascade/update tests)
- httpapi: DELETE /tasks/{id}, DELETE /tasks/{id}/accounts/{accountId},
  PUT /endpoints/{id}; delete guarded with 409 while task running
- orchestrator: enrich WS events with login/host/port/error (test + run + errors)
- web: delete buttons (task, account) with confirm, endpoint edit form,
  human-readable event log (source/dest, host:port, error text)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MMHQTtnQtQqL8muAXHr9kd

web/src/pages/TaskDetail.tsx

@@ -1,16 +1,45 @@
 import { useEffect, useRef, useState, type ChangeEvent, type FormEvent } from 'react'
-import { createAccount, getTask, importCSV, runTask, testAccounts, type TaskDetail as TaskDetailData } from '../api'
+import { createAccount, deleteAccount, getTask, importCSV, runTask, testAccounts, type TaskDetail as TaskDetailData } from '../api'
 import { connectTaskWS, type TaskEvent } from '../ws'
 import { StatusBadge } from '../components/StatusBadge'
 
 const emptyAccount = { src_login: '', src_pass: '', dst_login: '', dst_pass: '' }
 
+// Human-readable one-line description of a task event for the log panel.
+function describeEvent(ev: TaskEvent): string {
+  const d = (ev.data ?? {}) as Record<string, unknown>
+  const at = d.host ? `${d.login ?? ''}@${d.host}:${d.port}` : ''
+  switch (ev.type) {
+    case 'account_test': {
+      const where = d.side === 'src' ? 'SOURCE' : 'DEST'
+      const base = `${where} test ${String(d.status).toUpperCase()} — ${at}`
+      return d.error ? `${base} — ${d.error}` : base
+    }
+    case 'account_started':
+      return `START #${d.account_id}: ${d.src_login}@${d.src_host}:${d.src_port} → ${d.dst_login}@${d.dst_host}:${d.dst_port}`
+    case 'account_done':
+      return `DONE #${d.account_id} (${d.src_login} → ${d.dst_login}): copied ${d.copied}, skipped ${d.skipped}, errors ${d.errors}`
+    case 'progress':
+      return `progress #${d.account_id}: copied ${d.copied}, skipped ${d.skipped}`
+    case 'error': {
+      const where = d.folder ? ` folder "${d.folder}"` : d.side ? ` (${d.side} ${at})` : ''
+      return `ERROR #${d.account_id}${where}: ${d.error}`
+    }
+    case 'run_started':
+      return `RUN started (run #${d.run_id})`
+    case 'run_done':
+      return `RUN finished: copied ${d.copied}, skipped ${d.skipped}, errors ${d.errors}`
+    default:
+      return JSON.stringify(ev.data)
+  }
+}
+
 export function TaskDetail({ id }: { id: number }) {
   const [data, setData] = useState<TaskDetailData | null>(null)
   const [notFound, setNotFound] = useState(false)
   const [log, setLog] = useState<{ type: string; text: string }[]>([])
   const [form, setForm] = useState(emptyAccount)
-  const [busy, setBusy] = useState<'test' | 'run' | 'add' | 'import' | null>(null)
+  const [busy, setBusy] = useState<'test' | 'run' | 'add' | 'import' | 'delete' | null>(null)
   const [error, setError] = useState<string | null>(null)
   const fileInputRef = useRef<HTMLInputElement>(null)
 
@@ -28,7 +57,7 @@ export function TaskDetail({ id }: { id: number }) {
   useEffect(
     () =>
       connectTaskWS(id, (ev: TaskEvent) => {
-        setLog((l) => [{ type: ev.type, text: JSON.stringify(ev.data) }, ...l].slice(0, 300))
+        setLog((l) => [{ type: ev.type, text: describeEvent(ev) }, ...l].slice(0, 300))
         if (['account_started', 'account_test', 'account_done', 'progress', 'run_started', 'run_done', 'error'].includes(ev.type)) {
           reload()
         }
@@ -81,6 +110,20 @@ export function TaskDetail({ id }: { id: number }) {
     }
   }
 
+  async function onDeleteAccount(accId: number, login: string) {
+    if (!confirm(`Remove account "${login}" from this task?`)) return
+    setBusy('delete')
+    setError(null)
+    try {
+      await deleteAccount(id, accId)
+      reload()
+    } catch (err) {
+      setError(err instanceof Error ? err.message : 'Failed to remove account')
+    } finally {
+      setBusy(null)
+    }
+  }
+
   async function onTest() {
     setBusy('test')
     setError(null)
@@ -269,12 +312,13 @@ export function TaskDetail({ id }: { id: number }) {
                 <th>Copied</th>
                 <th>Skipped</th>
                 <th>Errors</th>
+                <th></th>
               </tr>
             </thead>
             <tbody>
               {accounts.length === 0 ? (
                 <tr className="empty-row">
-                  <td colSpan={8}>no accounts yet — add one or import a CSV above</td>
+                  <td colSpan={9}>no accounts yet — add one or import a CSV above</td>
                 </tr>
               ) : (
                 accounts.map((a) => (
@@ -293,6 +337,16 @@ export function TaskDetail({ id }: { id: number }) {
                     <td className="num-cell">{a.copied}</td>
                     <td className="num-cell">{a.skipped}</td>
                     <td className="num-cell">{a.errors}</td>
+                    <td className="num-cell">
+                      <button
+                        type="button"
+                        className="link-btn danger"
+                        onClick={() => onDeleteAccount(a.id, a.src_login)}
+                        disabled={busy !== null || data?.task.status === 'running'}
+                      >
+                        remove
+                      </button>
+                    </td>
                   </tr>
                 ))
               )}