Add stacked account display and fixed live progress row sizing

Improve account display by showing source/destination in a stacked format
when they differ, and add fixed sizing for live progress rows to prevent
resizing during scans. Also update the table header to use a single
"Account" column.

.gitignore

@@ -6,3 +6,7 @@
 !/internal/httpapi/webdist/index.html
 
 .DS_Store
+
+# local cache of the impeccable design hook
+.impeccable/
+**/.impeccable/

docker-compose-traefik.yml

@@ -23,7 +23,7 @@ services:
       AUTH_PASS: ${AUTH_PASS}
       ENC_KEY: ${ENC_KEY}
       SESSION_SECRET: ${SESSION_SECRET}
-      WORKER_CONCURRENCY: ${WORKER_CONCURRENCY:-4}
+      WORKER_CONCURRENCY: ${WORKER_CONCURRENCY:-2}
       PPROF_ADDR: ${PPROF_ADDR:-:6060}
     depends_on:
       postgres:

docs/superpowers/specs/2026-07-05-account-errors-modal-design.md

@@ -0,0 +1,100 @@
+# Account Errors Modal — Design
+
+Date: 2026-07-05
+Status: approved
+
+## Problem
+
+When an account finishes `done_with_errors`, the UI shows only an error **count**
+(e.g. `2`) and a single persisted `last_error`. There is no way to see the
+individual errors — which folder, which message, and the actual error text. The
+event log holds them live but is lost on reload, and message-level errors
+(`res.Errors`) currently record only a counter, discarding their text entirely.
+
+## Goal
+
+Click the ERRORS count of an account (when `> 0`) to open a modal listing the
+concrete errors of that account's **most recent run**: folder, kind, message
+reference, error text, and timestamp.
+
+## Scope decisions
+
+- **Coverage:** errors of the latest run only. The list is cleared at the start
+  of each run (like the per-account counters).
+- **Granularity:** every error is its own record — folder-level, message-level,
+  and account-level (connect/login) are distinct rows.
+- **Cap:** at most 500 error rows per account per run (guard against a corrupt
+  mailbox producing thousands). On overflow a final synthetic row records
+  "… N more errors suppressed".
+
+## Data model
+
+New table (chosen over a JSONB column on `accounts`): a table gives atomic
+`INSERT` per error with no read-modify-write races, trivial per-run clearing,
+`ON DELETE CASCADE` with the account, and matches the existing `runs` /
+`migrated_messages` shape.
+
+Migration `0005_account_errors`:
+
+```
+account_errors(
+  id          BIGSERIAL PRIMARY KEY,
+  account_id  BIGINT NOT NULL REFERENCES accounts(id) ON DELETE CASCADE,
+  run_id      BIGINT,                       -- run the error belongs to (context)
+  kind        TEXT NOT NULL,                -- 'folder' | 'message' | 'account'
+  folder      TEXT NOT NULL DEFAULT '',
+  message_ref TEXT NOT NULL DEFAULT '',     -- e.g. "UID 42: <subject>"
+  error       TEXT NOT NULL,
+  created_at  TIMESTAMPTZ NOT NULL DEFAULT now()
+)
+CREATE INDEX ON account_errors(account_id);
+```
+
+Down migration: `DROP TABLE account_errors`.
+
+## Backend
+
+**Store** (`internal/store/account_errors.go`):
+- `AddAccountError(ctx, accountID, runID int64, kind, folder, ref, msg string) error`
+- `ClearAccountErrors(ctx, accountID int64) error`
+- `ListAccountErrors(ctx, accountID int64) ([]AccountError, error)` — ordered by id.
+- `AccountError` struct mirrors the row.
+
+**Orchestrator** (`internal/orchestrator/orchestrator.go`):
+- At account start (next to `ResetAccountCounters`): `ClearAccountErrors`.
+- New `CopyDeps.OnError(kind, folder, ref, msg string)` callback. `CopyFolder`
+  invokes it on every message-level error (the `res.Errors++` sites in
+  `copy.go`) and folder-level error, passing UID/subject where available. The
+  orchestrator's `OnError` impl persists via `AddAccountError`, enforcing the
+  500-row cap with an in-worker counter.
+- Folder-level copy error (already persisted to `last_error`) also emits
+  `OnError(kind="folder", ...)`.
+- `accountFailed` (connect/login/decrypt) emits `OnError(kind="account", ...)`.
+- `last_error` behavior is unchanged (still the latest single error for the
+  inline row hint).
+
+**HTTP** (`internal/httpapi`):
+- `GET /api/tasks/{id}/accounts/{accountId}/errors` → JSON `[]AccountError`.
+
+## Frontend
+
+- `web/src/api.ts`: `listAccountErrors(taskId, accountId)`.
+- ERRORS cell becomes a button when the count `> 0`; opens `AccountErrorsModal`.
+- `web/src/components/AccountErrorsModal.tsx` (built on existing `Modal`,
+  styled like `RunLogModal`): fetches on open, renders rows
+  `time · folder · kind · message_ref · error`, with loading / empty /
+  fetch-error states.
+
+## Testing
+
+- Store: `AddAccountError` / `ClearAccountErrors` / `ListAccountErrors` against
+  Postgres (existing store test harness).
+- `CopyFolder`: `OnError` is invoked when a per-message step fails (e.g.
+  `IsMigrated` returns an error) — unit test with fakes, no server needed.
+- HTTP: handler returns the account's errors as JSON.
+
+## Out of scope
+
+- Cross-run error history.
+- Retrying individual failed messages from the modal.
+- Exporting errors.

internal/httpapi/accounts.go

@@ -226,6 +226,31 @@ func (s *Server) handleProbeAccountFolders(w http.ResponseWriter, r *http.Reques
 	})
 }
 
+// handleListAccountErrors returns the individual errors recorded for an account
+// during its most recent run, for the per-account error modal.
+func (s *Server) handleListAccountErrors(w http.ResponseWriter, r *http.Request) {
+	taskID, err := pathID(r, "id")
+	if err != nil {
+		http.Error(w, "bad id", http.StatusBadRequest)
+		return
+	}
+	accID, err := pathID(r, "accountId")
+	if err != nil {
+		http.Error(w, "bad account id", http.StatusBadRequest)
+		return
+	}
+	if _, ok := s.findAccount(r, taskID, accID); !ok {
+		http.Error(w, "account not found", http.StatusNotFound)
+		return
+	}
+	errs, err := s.store.ListAccountErrors(r.Context(), accID)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	writeJSON(w, http.StatusOK, errs)
+}
+
 // handleSetAccountFolderMapping persists one account's rename map + excluded set.
 func (s *Server) handleSetAccountFolderMapping(w http.ResponseWriter, r *http.Request) {
 	taskID, err := pathID(r, "id")

internal/httpapi/router.go

@@ -24,6 +24,7 @@ func (s *Server) Router() http.Handler {
 	api.HandleFunc("PUT /api/tasks/{id}/folder-mapping", s.handleSetFolderMapping)
 	api.HandleFunc("PUT /api/tasks/{id}/schedule", s.handleSetSchedule)
 	api.HandleFunc("GET /api/tasks/{id}/runs", s.handleListRuns)
+	api.HandleFunc("GET /api/tasks/{id}/accounts/{accountId}/errors", s.handleListAccountErrors)
 	api.HandleFunc("DELETE /api/tasks/{id}/accounts/{accountId}", s.handleDeleteAccount)
 	api.HandleFunc("POST /api/tasks/{id}/import", s.handleImportCSV)
 	api.HandleFunc("POST /api/tasks/{id}/test", s.handleTestAccounts)

internal/imapx/copy.go

@@ -27,6 +27,11 @@ type CopyDeps struct {
 	// folder's messages have been examined so far — so the UI shows movement
 	// while dedup decisions are made, before bodies start copying.
 	OnScan func(scanned, total int64)
+	// OnError is called for each message-level error, with a message reference
+	// ("UID N: subject", empty when the envelope is unavailable) and the error
+	// text — so the orchestrator can persist individual errors for the
+	// per-account error modal. Folder-level errors are reported by the caller.
+	OnError func(ref, msg string)
 }
 
 // CopyResult summarizes the outcome of one CopyFolder run.
@@ -44,6 +49,15 @@ type CopyResult struct {
 // checked between windows.
 const metaScanBatch = 1000
 
+// msgRef builds a human-readable reference for a message error: its UID plus
+// subject when known, e.g. "UID 42: Invoice". Falls back to just the UID.
+func msgRef(uid imap.UID, subject string) string {
+	if subject == "" {
+		return fmt.Sprintf("UID %d", uid)
+	}
+	return fmt.Sprintf("UID %d: %s", uid, subject)
+}
+
 // metaBatches tiles 1..total into contiguous, non-overlapping windows of at
 // most batchSize, covering every sequence number exactly once.
 func metaBatches(total, batchSize uint32) []imap.SeqRange {
@@ -95,11 +109,17 @@ func CopyFolder(ctx context.Context, src, dst *imapclient.Client, srcFolder, dst
 	type queued struct {
 		uid          imap.UID
 		key          string
+		subject      string
 		flags        []imap.Flag
 		internalDate time.Time
 	}
 	var todo []queued
 	var scanned int64
+	reportErr := func(ref, msg string) {
+		if deps.OnError != nil {
+			deps.OnError(ref, msg)
+		}
+	}
 	// Scan metadata in bounded windows instead of one FETCH 1:*, so each
 	// command is short (the server stays responsive) and ctx is checked on
 	// every window boundary — not just between messages of one giant command.
@@ -122,20 +142,26 @@ func CopyFolder(ctx context.Context, src, dst *imapclient.Client, srcFolder, dst
 			buf, err := msg.Collect()
 			if err != nil {
 				res.Errors++
+				reportErr("", "read message metadata: "+err.Error())
 				continue
 			}
 			scanned++
 			key := MessageKey(buf.Envelope, buf.RFC822Size)
+			subject := ""
+			if buf.Envelope != nil {
+				subject = buf.Envelope.Subject
+			}
 			already, err := deps.IsMigrated(key)
 			if err != nil {
 				res.Errors++
+				reportErr(msgRef(buf.UID, subject), "dedup lookup: "+err.Error())
 			} else if already {
 				res.Skipped++
 				if deps.OnProgress != nil {
 					deps.OnProgress(res.Copied, res.Skipped)
 				}
 			} else {
-				todo = append(todo, queued{uid: buf.UID, key: key, flags: buf.Flags, internalDate: buf.InternalDate})
+				todo = append(todo, queued{uid: buf.UID, key: key, subject: subject, flags: buf.Flags, internalDate: buf.InternalDate})
 			}
 			if deps.OnScan != nil {
 				deps.OnScan(scanned, total)
@@ -153,10 +179,12 @@ func CopyFolder(ctx context.Context, src, dst *imapclient.Client, srcFolder, dst
 		}
 		if err := streamOne(src, dst, dstFolder, q.uid, q.flags, q.internalDate); err != nil {
 			res.Errors++
+			reportErr(msgRef(q.uid, q.subject), "copy message: "+err.Error())
 			continue
 		}
 		if err := deps.MarkMigrated(dstFolder, q.key); err != nil {
 			res.Errors++
+			reportErr(msgRef(q.uid, q.subject), "mark migrated: "+err.Error())
 			continue
 		}
 		res.Copied++

internal/orchestrator/orchestrator.go

@@ -16,6 +16,12 @@ import (
 var ErrNotTested = errors.New("accounts not fully tested")
 var ErrAlreadyRunning = errors.New("task already running")
 
+// maxAccountErrors caps how many individual error rows one account records per
+// run, so a corrupt mailbox producing thousands of failures can't bloat the
+// account_errors table. The cap'th row is a synthetic "further errors
+// suppressed" note.
+const maxAccountErrors = 500
+
 // folderPlan is one source folder scheduled for copy and its destination name.
 type folderPlan struct {
 	src, dst string
@@ -264,6 +270,7 @@ func (o *Orchestrator) runAccount(ctx context.Context, task store.Task, runID in
 	_ = o.store.SetAccountStatus(ctx, a.ID, "running")
 	_ = o.store.SetAccountError(ctx, a.ID, "")     // clear any error from a previous run
 	_ = o.store.ResetAccountCounters(ctx, a.ID)    // start from zero; IncAccountCounters is additive
+	_ = o.store.ClearAccountErrors(ctx, a.ID)      // drop last run's per-error rows
 
 	// Per-account cancellable context: IMAP work uses actx (so CancelAccount
 	// stops it); DB writes keep the parent ctx so status/counters persist even
@@ -277,28 +284,28 @@ func (o *Orchestrator) runAccount(ctx context.Context, task store.Task, runID in
 
 	srcPass, err := crypto.Decrypt(o.encKey, a.SrcPassEnc)
 	if err != nil {
-		return o.accountFailed(ctx, task.ID, a, srcEP, dstEP, "src", err)
+		return o.accountFailed(ctx, task.ID, runID, a, srcEP, dstEP, "src", err)
 	}
 	dstPass, err := crypto.Decrypt(o.encKey, a.DstPassEnc)
 	if err != nil {
-		return o.accountFailed(ctx, task.ID, a, srcEP, dstEP, "dst", err)
+		return o.accountFailed(ctx, task.ID, runID, a, srcEP, dstEP, "dst", err)
 	}
 
 	src, err := imapx.Connect(actx, srcEP)
 	if err != nil {
-		return o.accountFailed(ctx, task.ID, a, srcEP, dstEP, "src", err)
+		return o.accountFailed(ctx, task.ID, runID, a, srcEP, dstEP, "src", err)
 	}
 	defer func() { _ = src.Logout().Wait() }()
 	if err := src.Login(a.SrcLogin, string(srcPass)).Wait(); err != nil {
-		return o.accountFailed(ctx, task.ID, a, srcEP, dstEP, "src", err)
+		return o.accountFailed(ctx, task.ID, runID, a, srcEP, dstEP, "src", err)
 	}
 	dst, err := imapx.Connect(actx, dstEP)
 	if err != nil {
-		return o.accountFailed(ctx, task.ID, a, srcEP, dstEP, "dst", err)
+		return o.accountFailed(ctx, task.ID, runID, a, srcEP, dstEP, "dst", err)
 	}
 	defer func() { _ = dst.Logout().Wait() }()
 	if err := dst.Login(a.DstLogin, string(dstPass)).Wait(); err != nil {
-		return o.accountFailed(ctx, task.ID, a, srcEP, dstEP, "dst", err)
+		return o.accountFailed(ctx, task.ID, runID, a, srcEP, dstEP, "dst", err)
 	}
 
 	// On cancel, close the connections so any in-flight network read (a slow
@@ -311,7 +318,7 @@ func (o *Orchestrator) runAccount(ctx context.Context, task store.Task, runID in
 
 	folders, err := imapx.ListFolders(src)
 	if err != nil {
-		return o.accountFailed(ctx, task.ID, a, srcEP, dstEP, "src", err)
+		return o.accountFailed(ctx, task.ID, runID, a, srcEP, dstEP, "src", err)
 	}
 
 	// Planning pass: decide folders from the account's own config, then EXAMINE
@@ -341,9 +348,24 @@ func (o *Orchestrator) runAccount(ctx context.Context, task store.Task, runID in
 	var curFolder string
 	var curTotal int64
 	var lastEmit, lastScanEmit time.Time
+	// Persist individual errors for the per-account error modal, capped so a
+	// corrupt mailbox can't write unbounded rows. Runs on this goroutine, so
+	// the counter is race-free (same reasoning as the progress vars above).
+	var persistedErrs int
+	addErr := func(kind, folder, ref, msg string) {
+		persistedErrs++
+		switch {
+		case persistedErrs < maxAccountErrors:
+			_ = o.store.AddAccountError(ctx, a.ID, runID, kind, folder, ref, msg)
+		case persistedErrs == maxAccountErrors:
+			_ = o.store.AddAccountError(ctx, a.ID, runID, "account", "", "",
+				"too many errors — further errors suppressed")
+		}
+	}
 	deps := imapx.CopyDeps{
 		IsMigrated:   func(k string) (bool, error) { return o.store.IsMigrated(ctx, a.ID, k) },
 		MarkMigrated: func(folder, k string) error { return o.store.MarkMigrated(ctx, a.ID, folder, k) },
+		OnError:      func(ref, msg string) { addErr("message", curFolder, ref, msg) },
 		OnProgress: func(c, s int) {
 			now := time.Now()
 			done := c + s
@@ -393,6 +415,7 @@ func (o *Orchestrator) runAccount(ctx context.Context, task store.Task, runID in
 			slog.Warn("folder copy error", "account", a.ID, "src_login", a.SrcLogin, "folder", fp.src, "err", err)
 			folderErr = 1
 			_ = o.store.SetAccountError(ctx, a.ID, "folder \""+fp.src+"\": "+err.Error())
+			addErr("folder", fp.src, "", err.Error())
 			o.hub.Publish(wshub.Event{Type: "error", TaskID: task.ID, Data: map[string]any{
 				"account_id": a.ID, "src_login": a.SrcLogin, "folder": fp.src, "error": err.Error(),
 			}})
@@ -428,7 +451,7 @@ func (o *Orchestrator) runAccount(ctx context.Context, task store.Task, runID in
 	return copied, skipped, errs
 }
 
-func (o *Orchestrator) accountFailed(ctx context.Context, taskID int64, a store.Account, srcEP, dstEP imapx.Endpoint, side string, err error) (int64, int64, int64) {
+func (o *Orchestrator) accountFailed(ctx context.Context, taskID, runID int64, a store.Account, srcEP, dstEP imapx.Endpoint, side string, err error) (int64, int64, int64) {
 	// A cancellation surfacing as an error is a cancel, not a failure.
 	if errors.Is(err, context.Canceled) {
 		_ = o.store.SetAccountStatus(ctx, a.ID, "cancelled")
@@ -442,7 +465,9 @@ func (o *Orchestrator) accountFailed(ctx context.Context, taskID int64, a store.
 	}
 	slog.Error("account failed", "account", a.ID, "side", side, "login", login, "host", host, "port", port, "err", err)
 	_ = o.store.SetAccountStatus(ctx, a.ID, "error")
-	_ = o.store.SetAccountError(ctx, a.ID, side+" "+login+"@"+host+": "+err.Error())
+	failMsg := side + " " + login + "@" + host + ": " + err.Error()
+	_ = o.store.SetAccountError(ctx, a.ID, failMsg)
+	_ = o.store.AddAccountError(ctx, a.ID, runID, "account", "", "", failMsg)
 	o.hub.Publish(wshub.Event{Type: "error", TaskID: taskID,
 		Data: map[string]any{"account_id": a.ID, "side": side, "login": login, "host": host, "port": port, "error": err.Error()}})
 	return 0, 0, 1

internal/store/account_errors.go

@@ -0,0 +1,61 @@
+package store
+
+import (
+	"context"
+	"time"
+)
+
+// AccountError is one concrete error recorded during an account's run —
+// folder-level, message-level, or account-level (connect/login).
+type AccountError struct {
+	ID         int64     `json:"id"`
+	AccountID  int64     `json:"account_id"`
+	RunID      int64     `json:"run_id"`
+	Kind       string    `json:"kind"` // folder | message | account
+	Folder     string    `json:"folder"`
+	MessageRef string    `json:"message_ref"`
+	Error      string    `json:"error"`
+	CreatedAt  time.Time `json:"created_at"`
+}
+
+// AddAccountError appends one error row for an account's current run.
+func (s *Store) AddAccountError(ctx context.Context, accountID, runID int64, kind, folder, ref, msg string) error {
+	_, err := s.Pool.Exec(ctx,
+		`INSERT INTO account_errors (account_id, run_id, kind, folder, message_ref, error)
+		 VALUES ($1,$2,$3,$4,$5,$6)`,
+		accountID, runID, kind, folder, ref, msg)
+	return err
+}
+
+// ClearAccountErrors removes an account's errors at the start of a run, so the
+// list reflects only the current run (mirrors ResetAccountCounters).
+func (s *Store) ClearAccountErrors(ctx context.Context, accountID int64) error {
+	_, err := s.Pool.Exec(ctx, `DELETE FROM account_errors WHERE account_id=$1`, accountID)
+	return err
+}
+
+// ListAccountErrors returns an account's errors in insertion order, for the
+// per-account error modal.
+func (s *Store) ListAccountErrors(ctx context.Context, accountID int64) ([]AccountError, error) {
+	rows, err := s.Pool.Query(ctx,
+		`SELECT id, account_id, run_id, kind, folder, message_ref, error, created_at
+		 FROM account_errors WHERE account_id=$1 ORDER BY id`, accountID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	out := []AccountError{}
+	for rows.Next() {
+		var e AccountError
+		var runID *int64
+		if err := rows.Scan(&e.ID, &e.AccountID, &runID, &e.Kind, &e.Folder,
+			&e.MessageRef, &e.Error, &e.CreatedAt); err != nil {
+			return nil, err
+		}
+		if runID != nil {
+			e.RunID = *runID
+		}
+		out = append(out, e)
+	}
+	return out, rows.Err()
+}

internal/store/account_errors_test.go

@@ -0,0 +1,75 @@
+package store
+
+import (
+	"context"
+	"testing"
+)
+
+// AddAccountError persists individual errors; ListAccountErrors returns them in
+// insertion order; ClearAccountErrors wipes them for the next run.
+func TestAccountErrorsAddListClear(t *testing.T) {
+	s := testStore(t)
+	ctx := context.Background()
+	epSrc, _ := s.CreateEndpoint(ctx, Endpoint{RoleLabel: "src", Host: "a", Port: 993, TLSMode: "ssl"})
+	epDst, _ := s.CreateEndpoint(ctx, Endpoint{RoleLabel: "dst", Host: "b", Port: 993, TLSMode: "ssl"})
+	taskID, _ := s.CreateTask(ctx, Task{Name: "t", SrcEndpointID: epSrc, DstEndpointID: epDst})
+	runID, _ := s.CreateRun(ctx, taskID, "manual")
+	accID, _ := s.CreateAccount(ctx, Account{TaskID: taskID, SrcLogin: "u", SrcPassEnc: "x", DstLogin: "u2", DstPassEnc: "y"})
+
+	if err := s.AddAccountError(ctx, accID, runID, "folder", "INBOX", "", "examine failed"); err != nil {
+		t.Fatalf("add folder: %v", err)
+	}
+	if err := s.AddAccountError(ctx, accID, runID, "message", "INBOX", "UID 42: hi", "append rejected"); err != nil {
+		t.Fatalf("add message: %v", err)
+	}
+
+	errs, err := s.ListAccountErrors(ctx, accID)
+	if err != nil {
+		t.Fatalf("list: %v", err)
+	}
+	if len(errs) != 2 {
+		t.Fatalf("len=%d want 2", len(errs))
+	}
+	if errs[0].Kind != "folder" || errs[0].Folder != "INBOX" || errs[0].Error != "examine failed" {
+		t.Fatalf("errs[0]=%+v", errs[0])
+	}
+	if errs[1].Kind != "message" || errs[1].MessageRef != "UID 42: hi" || errs[1].Error != "append rejected" {
+		t.Fatalf("errs[1]=%+v", errs[1])
+	}
+	if errs[0].ID >= errs[1].ID {
+		t.Fatalf("expected insertion order by id: %d then %d", errs[0].ID, errs[1].ID)
+	}
+
+	if err := s.ClearAccountErrors(ctx, accID); err != nil {
+		t.Fatalf("clear: %v", err)
+	}
+	errs, err = s.ListAccountErrors(ctx, accID)
+	if err != nil {
+		t.Fatalf("list after clear: %v", err)
+	}
+	if len(errs) != 0 {
+		t.Fatalf("after clear len=%d want 0", len(errs))
+	}
+}
+
+// Deleting an account cascades its errors (ON DELETE CASCADE).
+func TestAccountErrorsCascadeOnAccountDelete(t *testing.T) {
+	s := testStore(t)
+	ctx := context.Background()
+	epSrc, _ := s.CreateEndpoint(ctx, Endpoint{RoleLabel: "src", Host: "a", Port: 993, TLSMode: "ssl"})
+	epDst, _ := s.CreateEndpoint(ctx, Endpoint{RoleLabel: "dst", Host: "b", Port: 993, TLSMode: "ssl"})
+	taskID, _ := s.CreateTask(ctx, Task{Name: "t", SrcEndpointID: epSrc, DstEndpointID: epDst})
+	accID, _ := s.CreateAccount(ctx, Account{TaskID: taskID, SrcLogin: "u", SrcPassEnc: "x", DstLogin: "u2", DstPassEnc: "y"})
+	_ = s.AddAccountError(ctx, accID, 0, "account", "", "", "login failed")
+
+	if err := s.DeleteAccount(ctx, accID); err != nil {
+		t.Fatalf("delete: %v", err)
+	}
+	var n int
+	if err := s.Pool.QueryRow(ctx, `SELECT count(*) FROM account_errors WHERE account_id=$1`, accID).Scan(&n); err != nil {
+		t.Fatalf("count: %v", err)
+	}
+	if n != 0 {
+		t.Fatalf("account_errors not cascaded: %d rows", n)
+	}
+}

internal/store/store_test.go

@@ -17,7 +17,7 @@ func testStore(t *testing.T) *Store {
 	}
 	t.Cleanup(func() {
 		s.Pool.Exec(context.Background(),
-			`TRUNCATE endpoints, tasks, accounts, runs, migrated_messages RESTART IDENTITY CASCADE`)
+			`TRUNCATE endpoints, tasks, accounts, runs, migrated_messages, account_errors RESTART IDENTITY CASCADE`)
 		s.Pool.Close()
 	})
 	return s

migrations/0005_account_errors.down.sql

@@ -0,0 +1 @@
+DROP TABLE account_errors;

migrations/0005_account_errors.up.sql

@@ -0,0 +1,12 @@
+CREATE TABLE account_errors (
+    id          BIGSERIAL PRIMARY KEY,
+    account_id  BIGINT NOT NULL REFERENCES accounts(id) ON DELETE CASCADE,
+    run_id      BIGINT,
+    kind        TEXT NOT NULL CHECK (kind IN ('folder','message','account')),
+    folder      TEXT NOT NULL DEFAULT '',
+    message_ref TEXT NOT NULL DEFAULT '',
+    error       TEXT NOT NULL,
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE INDEX account_errors_account_id_idx ON account_errors (account_id);

web/src/api.ts

@@ -157,6 +157,20 @@ export const setTaskSchedule = (taskId: number, intervalSeconds: number) =>
 
 export const listRuns = (taskId: number) => api<Run[]>(`/api/tasks/${taskId}/runs`)
 
+export interface AccountError {
+  id: number
+  account_id: number
+  run_id: number
+  kind: string // folder | message | account
+  folder: string
+  message_ref: string
+  error: string
+  created_at: string
+}
+
+export const listAccountErrors = (taskId: number, accountId: number) =>
+  api<AccountError[]>(`/api/tasks/${taskId}/accounts/${accountId}/errors`)
+
 export const importCSV = (id: number, file: File) => {
   const fd = new FormData()
   fd.append('file', file)

web/src/app.css

@@ -255,11 +255,36 @@
 }
 
 /* per-account live progress */
+/* merged Source/Destination "Account" cell: single line when src == dst,
+   stacked (src over dst) when they differ. */
+.acct-ident {
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+}
+
+.acct-dst {
+  color: var(--fg-dim);
+  font-size: 12px;
+}
+
 .acct-progress {
   display: flex;
   flex-direction: column;
   gap: 4px;
   min-width: 160px;
+  /* reserve room for the bar + two meta lines so toggling the scan line
+     during a run doesn't change the row height */
+  min-height: 40px;
+}
+
+/* Running rows get a fixed wide size up front so live progress updates
+   (which change text length and can wrap) never resize the row mid-scan.
+   The size reverts only when the run finishes and the class drops. */
+.progress-cell--live {
+  min-width: 340px;
+  height: 48px;
+  vertical-align: top;
 }
 
 .pbar {
@@ -283,6 +308,8 @@
   font-size: 10px;
   color: var(--fg-dim);
   letter-spacing: 0.04em;
+  /* keep progress text on one line so its length never reflows the row */
+  white-space: nowrap;
 }
 
 .pscan {
@@ -300,6 +327,16 @@
   white-space: nowrap;
 }
 
+/* error text inside the per-account errors modal: wrap long messages */
+.err-cell {
+  max-width: 420px;
+  white-space: normal;
+  word-break: break-word;
+  color: var(--fail);
+  font-size: 12px;
+  line-height: 1.4;
+}
+
 /* clear-log button: mirrors the .panel-label tab on the right edge */
 .log-clear {
   position: absolute;

web/src/components/AccountErrorsModal.tsx

@@ -0,0 +1,65 @@
+import { useEffect, useState } from 'react'
+import { Modal } from './Modal'
+import { listAccountErrors, type AccountError } from '../api'
+
+const fmt = (iso: string) => (iso ? new Date(iso).toLocaleString() : '—')
+
+export function AccountErrorsModal({
+  taskId,
+  account,
+  onClose,
+}: {
+  taskId: number
+  account: { id: number; src_login: string } | null
+  onClose: () => void
+}) {
+  const [errors, setErrors] = useState<AccountError[] | null>(null)
+  const [failed, setFailed] = useState(false)
+  const open = account !== null
+
+  useEffect(() => {
+    if (!account) return
+    setErrors(null)
+    setFailed(false)
+    listAccountErrors(taskId, account.id)
+      .then((e) => setErrors(e ?? []))
+      .catch(() => setFailed(true))
+  }, [taskId, account])
+
+  return (
+    <Modal open={open} title={account ? `Errors — ${account.src_login}` : 'Errors'} onClose={onClose} size="lg">
+      <div className="tbl-wrap">
+        <table className="tbl">
+          <thead>
+            <tr>
+              <th>Time</th>
+              <th>Kind</th>
+              <th>Folder</th>
+              <th>Message</th>
+              <th>Error</th>
+            </tr>
+          </thead>
+          <tbody>
+            {failed ? (
+              <tr className="empty-row"><td colSpan={5}>failed to load errors</td></tr>
+            ) : errors === null ? (
+              <tr className="empty-row"><td colSpan={5}>loading…</td></tr>
+            ) : errors.length === 0 ? (
+              <tr className="empty-row"><td colSpan={5}>no errors recorded</td></tr>
+            ) : (
+              errors.map((e) => (
+                <tr key={e.id}>
+                  <td>{fmt(e.created_at)}</td>
+                  <td>{e.kind}</td>
+                  <td>{e.folder || '—'}</td>
+                  <td>{e.message_ref || '—'}</td>
+                  <td className="err-cell">{e.error}</td>
+                </tr>
+              ))
+            )}
+          </tbody>
+        </table>
+      </div>
+    </Modal>
+  )
+}

web/src/pages/TaskDetail.tsx

@@ -5,6 +5,7 @@ import { StatusBadge } from '../components/StatusBadge'
 import { useConfirm } from '../components/ConfirmProvider'
 import { FolderMappingModal } from '../components/FolderMappingModal'
 import { RunLogModal } from '../components/RunLogModal'
+import { AccountErrorsModal } from '../components/AccountErrorsModal'
 
 const emptyAccount = { src_login: '', src_pass: '', dst_login: '', dst_pass: '' }
 
@@ -87,6 +88,7 @@ export function TaskDetail({ id }: { id: number }) {
   const [error, setError] = useState<string | null>(null)
   const [live, setLive] = useState<Record<number, LiveProgress>>({})
   const [showRuns, setShowRuns] = useState(false)
+  const [errorsFor, setErrorsFor] = useState<{ id: number; src_login: string } | null>(null)
   const fileInputRef = useRef<HTMLInputElement>(null)
 
   function reload() {
@@ -536,8 +538,7 @@ export function TaskDetail({ id }: { id: number }) {
           <table className="tbl">
             <thead>
               <tr>
-                <th>Source</th>
+                <th>Account</th>
-                <th>Destination</th>
                 <th>Src test</th>
                 <th>Dst test</th>
                 <th>Status</th>
@@ -551,20 +552,24 @@ export function TaskDetail({ id }: { id: number }) {
             <tbody>
               {accounts.length === 0 ? (
                 <tr className="empty-row">
-                  <td colSpan={10}>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) => (
                   <tr key={a.id}>
                     <td>
-                      {a.src_login}
+                      <div className="acct-ident">
+                        <span>{a.src_login}</span>
+                        {a.dst_login !== a.src_login && (
+                          <span className="acct-dst">→ {a.dst_login}</span>
+                        )}
+                      </div>
                       {a.last_error && (
                         <div className="acct-error" title={a.last_error}>
                           {a.last_error}
                         </div>
                       )}
                     </td>
-                    <td>{a.dst_login}</td>
                     <td>
                       <StatusBadge status={a.test_src_status} />
                     </td>
@@ -574,7 +579,7 @@ export function TaskDetail({ id }: { id: number }) {
                     <td>
                       <StatusBadge status={a.status} />
                     </td>
-                    <td className="progress-cell">
+                    <td className={`progress-cell${a.status === 'running' ? ' progress-cell--live' : ''}`}>
                       {(() => {
                         const lv = live[a.id]
                         if (!lv || !lv.total) return <span className="muted-note">—</span>
@@ -609,7 +614,19 @@ export function TaskDetail({ id }: { id: number }) {
                     </td>
                     <td className="num-cell">{live[a.id]?.copied ?? a.copied}</td>
                     <td className="num-cell">{live[a.id]?.skipped ?? a.skipped}</td>
-                    <td className="num-cell">{a.errors}</td>
+                    <td className="num-cell">
+                      {a.errors > 0 ? (
+                        <button
+                          type="button"
+                          className="link-btn danger"
+                          onClick={() => setErrorsFor({ id: a.id, src_login: a.src_login })}
+                        >
+                          {a.errors}
+                        </button>
+                      ) : (
+                        a.errors
+                      )}
+                    </td>
                     <td className="num-cell">
                       <div className="row-actions">
                         {a.status !== 'running' && data?.task.status !== 'running' && (
@@ -671,6 +688,7 @@ export function TaskDetail({ id }: { id: number }) {
         />
       )}
       <RunLogModal taskId={id} open={showRuns} onClose={() => setShowRuns(false)} />
+      <AccountErrorsModal taskId={id} account={errorsFor} onClose={() => setErrorsFor(null)} />
     </>
   )
 }