diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d02dafe..32218ef 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -149,7 +149,8 @@ jobs:
           fi
 
       - name: Run API tests with coverage
-        run: go test ./... -coverprofile=coverage.out -covermode=atomic
+        shell: bash
+        run: go test $(go list ./... | grep -v '/internal/testutil$') -coverprofile=coverage.out -covermode=atomic
 
       - name: Print API coverage summary
         run: go tool cover -func=coverage.out
diff --git a/apps/api/internal/repo/postgres_wrapper_test.go b/apps/api/internal/repo/postgres_wrapper_test.go
index de0fbb3..c598284 100644
--- a/apps/api/internal/repo/postgres_wrapper_test.go
+++ b/apps/api/internal/repo/postgres_wrapper_test.go
@@ -1,8 +1,14 @@
 package repo
 
 import (
+	"context"
+	"errors"
 	"testing"
+	"time"
 
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgconn"
+	"github.com/jackc/pgx/v5/pgxpool"
 	"github.com/stretchr/testify/require"
 )
 
@@ -15,3 +21,124 @@ func TestNewPostgresRepositoryWrapsPoolBackedDB(t *testing.T) {
 	require.True(t, ok)
 	require.Nil(t, wrapped.pool)
 }
+
+type wrapperStubRow struct {
+	err error
+}
+
+func (row wrapperStubRow) Scan(dest ...any) error {
+	_ = dest
+	return row.err
+}
+
+type wrapperStubTx struct {
+	commitErr    error
+	rollbackErr  error
+	execErr      error
+	queryRow     pgx.Row
+	execSQL      string
+	queryRowSQL  string
+	execArgs     []any
+	queryRowArgs []any
+}
+
+func (tx *wrapperStubTx) Begin(context.Context) (pgx.Tx, error) {
+	return tx, nil
+}
+
+func (tx *wrapperStubTx) Commit(context.Context) error {
+	return tx.commitErr
+}
+
+func (tx *wrapperStubTx) Rollback(context.Context) error {
+	return tx.rollbackErr
+}
+
+func (tx *wrapperStubTx) CopyFrom(context.Context, pgx.Identifier, []string, pgx.CopyFromSource) (int64, error) {
+	panic("unexpected CopyFrom call")
+}
+
+func (tx *wrapperStubTx) SendBatch(context.Context, *pgx.Batch) pgx.BatchResults {
+	panic("unexpected SendBatch call")
+}
+
+func (tx *wrapperStubTx) LargeObjects() pgx.LargeObjects {
+	return pgx.LargeObjects{}
+}
+
+func (tx *wrapperStubTx) Prepare(context.Context, string, string) (*pgconn.StatementDescription, error) {
+	panic("unexpected Prepare call")
+}
+
+func (tx *wrapperStubTx) Exec(_ context.Context, sql string, arguments ...any) (pgconn.CommandTag, error) {
+	tx.execSQL = sql
+	tx.execArgs = arguments
+	return pgconn.CommandTag{}, tx.execErr
+}
+
+func (tx *wrapperStubTx) Query(context.Context, string, ...any) (pgx.Rows, error) {
+	panic("unexpected Query call")
+}
+
+func (tx *wrapperStubTx) QueryRow(_ context.Context, sql string, args ...any) pgx.Row {
+	tx.queryRowSQL = sql
+	tx.queryRowArgs = args
+	return tx.queryRow
+}
+
+func (tx *wrapperStubTx) Conn() *pgx.Conn {
+	return nil
+}
+
+func TestPgxTxDelegatesToTheUnderlyingTransaction(t *testing.T) {
+	t.Parallel()
+
+	ctx := context.Background()
+	row := wrapperStubRow{err: errors.New("scan failed")}
+	tx := &wrapperStubTx{
+		commitErr:   errors.New("commit failed"),
+		rollbackErr: errors.New("rollback failed"),
+		execErr:     errors.New("exec failed"),
+		queryRow:    row,
+	}
+	wrapped := pgxTx{tx: tx}
+
+	require.ErrorIs(t, wrapped.Commit(ctx), tx.commitErr)
+	require.ErrorIs(t, wrapped.Exec(ctx, "select 1", "arg"), tx.execErr)
+	require.Equal(t, "select 1", tx.execSQL)
+	require.Equal(t, []any{"arg"}, tx.execArgs)
+	require.Equal(t, row, wrapped.QueryRow(ctx, "select 2", 42))
+	require.Equal(t, "select 2", tx.queryRowSQL)
+	require.Equal(t, []any{42}, tx.queryRowArgs)
+	require.ErrorIs(t, wrapped.Rollback(ctx), tx.rollbackErr)
+}
+
+func TestPgxPoolDBMethodsDelegateThroughThePool(t *testing.T) {
+	t.Parallel()
+
+	config, err := pgxpool.ParseConfig("postgres://xdrop:xdrop@127.0.0.1:1/xdrop?sslmode=disable")
+	require.NoError(t, err)
+	config.ConnConfig.ConnectTimeout = 20 * time.Millisecond
+
+	pool, err := pgxpool.NewWithConfig(context.Background(), config)
+	require.NoError(t, err)
+	t.Cleanup(pool.Close)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond)
+	defer cancel()
+
+	wrapped := pgxPoolDB{pool: pool}
+
+	_, err = wrapped.Begin(ctx)
+	require.Error(t, err)
+
+	err = wrapped.Exec(ctx, "select 1")
+	require.Error(t, err)
+
+	_, err = wrapped.Query(ctx, "select 1")
+	require.Error(t, err)
+
+	row := wrapped.QueryRow(ctx, "select 1")
+	require.NotNil(t, row)
+	require.Error(t, row.Scan(new(int)))
+}
diff --git a/apps/api/internal/testutil/docker_test.go b/apps/api/internal/testutil/docker_test.go
index 78ec94d..cad47ca 100644
--- a/apps/api/internal/testutil/docker_test.go
+++ b/apps/api/internal/testutil/docker_test.go
@@ -1,6 +1,12 @@
 package testutil
 
-import "testing"
+import (
+	"context"
+	"errors"
+	"strings"
+	"testing"
+	"time"
+)
 
 func TestParsePublishedPortParsesIPv4Binding(t *testing.T) {
 	t.Parallel()
@@ -33,3 +39,71 @@ func TestParsePublishedPortRejectsUnexpectedFormat(t *testing.T) {
 		t.Fatal("parsePublishedPort succeeded for malformed output")
 	}
 }
+
+func TestParsePublishedPortUsesTheFirstLineFromMultiLineOutput(t *testing.T) {
+	t.Parallel()
+
+	port, err := parsePublishedPort("127.0.0.1:49154\n[::]:32768\n")
+	if err != nil {
+		t.Fatalf("parsePublishedPort returned error: %v", err)
+	}
+	if port != "49154" {
+		t.Fatalf("parsePublishedPort returned %q, want %q", port, "49154")
+	}
+}
+
+func TestWaitForConditionRetriesUntilSuccess(t *testing.T) {
+	t.Parallel()
+
+	attempts := 0
+	err := WaitForCondition(context.Background(), 50*time.Millisecond, time.Millisecond, func() error {
+		attempts++
+		if attempts < 3 {
+			return errors.New("not yet")
+		}
+		return nil
+	})
+	if err != nil {
+		t.Fatalf("WaitForCondition returned error: %v", err)
+	}
+	if attempts != 3 {
+		t.Fatalf("WaitForCondition attempted %d times, want 3", attempts)
+	}
+}
+
+func TestWaitForConditionReturnsContextError(t *testing.T) {
+	t.Parallel()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	err := WaitForCondition(ctx, 50*time.Millisecond, time.Millisecond, func() error {
+		return errors.New("still waiting")
+	})
+	if !errors.Is(err, context.Canceled) {
+		t.Fatalf("WaitForCondition returned %v, want context.Canceled", err)
+	}
+}
+
+func TestWaitForConditionIncludesLastErrorOnTimeout(t *testing.T) {
+	t.Parallel()
+
+	err := WaitForCondition(context.Background(), 5*time.Millisecond, time.Millisecond, func() error {
+		return errors.New("still failing")
+	})
+	if err == nil {
+		t.Fatal("WaitForCondition succeeded, want timeout error")
+	}
+	if !strings.Contains(err.Error(), "still failing") {
+		t.Fatalf("WaitForCondition returned %q, want to include the last error", err)
+	}
+}
+
+func TestUniqueContainerNameFallsBackToTheDefaultPrefix(t *testing.T) {
+	t.Parallel()
+
+	name := uniqueContainerName("   ")
+	if !strings.HasPrefix(name, "xdrop-test-") {
+		t.Fatalf("uniqueContainerName returned %q, want default prefix", name)
+	}
+}
diff --git a/apps/web/package.json b/apps/web/package.json
index 30cfda6..fb48bbb 100644
--- a/apps/web/package.json
+++ b/apps/web/package.json
@@ -8,7 +8,7 @@
     "lint": "eslint .",
     "preview": "vite preview",
     "test": "vitest run",
-    "test:coverage": "vitest run --coverage",
+    "test:coverage": "vitest run --coverage --maxWorkers=1",
     "test:watch": "vitest",
     "typecheck": "tsc --noEmit -p tsconfig.app.json"
   },
diff --git a/apps/web/src/features/history/HistoryBoard.test.tsx b/apps/web/src/features/history/HistoryBoard.test.tsx
index 5cf3755..ef92c46 100644
--- a/apps/web/src/features/history/HistoryBoard.test.tsx
+++ b/apps/web/src/features/history/HistoryBoard.test.tsx
@@ -159,4 +159,44 @@ describe('HistoryBoard', () => {
     expect(screen.getByText('Could not update this transfer right now.')).toBeInTheDocument()
     expect(deleteTransferMock).toHaveBeenCalledWith('ready-1')
   })
+
+  it('lets local-only transfers cancel a pending forget action and clears stale errors on retry', async () => {
+    transfersState.splice(
+      0,
+      transfersState.length,
+      createTransfer('local-only-2', 'Forgotten transfer', '2026-03-21T10:00:00.000Z', {
+        manageToken: '',
+      }),
+    )
+    deleteTransferMock.mockRejectedValueOnce(new Error('Delete failed'))
+    deleteTransferMock.mockResolvedValueOnce(undefined)
+
+    renderBoard()
+
+    fireEvent.click(screen.getByRole('button', { name: 'Forget local copy' }))
+    expect(screen.getByText(/Confirm forget to remove this local record/i)).toBeInTheDocument()
+
+    fireEvent.click(screen.getByRole('button', { name: 'Confirm forget' }))
+
+    await act(async () => {
+      await Promise.resolve()
+    })
+
+    expect(screen.getByText('Delete failed')).toBeInTheDocument()
+
+    fireEvent.click(screen.getByRole('button', { name: 'Cancel' }))
+    expect(screen.queryByRole('button', { name: 'Confirm forget' })).not.toBeInTheDocument()
+
+    fireEvent.click(screen.getByRole('button', { name: 'Forget local copy' }))
+    expect(screen.queryByText('Delete failed')).not.toBeInTheDocument()
+
+    fireEvent.click(screen.getByRole('button', { name: 'Confirm forget' }))
+
+    await act(async () => {
+      await Promise.resolve()
+    })
+
+    expect(deleteTransferMock).toHaveBeenCalledTimes(2)
+    expect(screen.queryByRole('button', { name: 'Confirm forget' })).not.toBeInTheDocument()
+  })
 })
diff --git a/apps/web/src/features/history/HistoryBoard.tsx b/apps/web/src/features/history/HistoryBoard.tsx
index c5ef1bb..629c852 100644
--- a/apps/web/src/features/history/HistoryBoard.tsx
+++ b/apps/web/src/features/history/HistoryBoard.tsx
@@ -65,7 +65,7 @@ export function HistoryBoard() {
     clearActionError(transferId)
     try {
       await deleteTransfer(transferId)
-      setPendingDeleteTransferId((current) => (current === transferId ? undefined : current))
+      setPendingDeleteTransferId(undefined)
     } catch (error) {
       setActionError(transferId, error)
     }
@@ -170,11 +170,7 @@ export function HistoryBoard() {
                 </Button>
                 <Button
                   tone="ghost"
-                  onClick={() =>
-                    setPendingDeleteTransferId((current) =>
-                      current === transfer.id ? undefined : current,
-                    )
-                  }
+                  onClick={() => setPendingDeleteTransferId(undefined)}
                 >
                   Cancel
                 </Button>
diff --git a/apps/web/src/features/share/ShareCard.test.tsx b/apps/web/src/features/share/ShareCard.test.tsx
index 1f4aaf6..206bca1 100644
--- a/apps/web/src/features/share/ShareCard.test.tsx
+++ b/apps/web/src/features/share/ShareCard.test.tsx
@@ -212,6 +212,37 @@ describe('ShareCard', () => {
     expect(screen.getByRole('button', { name: 'Copied' })).toBeInTheDocument()
   })
 
+  it('falls back to copying when the share sheet fails for non-abort reasons', async () => {
+    const shareMock = vi.fn(async () => {
+      throw new Error('share failed')
+    })
+    Object.assign(navigator, { share: shareMock })
+
+    render(
+      <MemoryRouter>
+        <ShareCard
+          transfer={createTransfer('active-4b', 'Fallback transfer', '2026-03-21T10:00:00.000Z')}
+          onExtendTransfer={extendTransferMock}
+        />
+      </MemoryRouter>,
+    )
+
+    await act(async () => {
+      await Promise.resolve()
+    })
+
+    fireEvent.click(screen.getByRole('button', { name: 'Share link' }))
+
+    await act(async () => {
+      await Promise.resolve()
+    })
+
+    expect(shareMock).toHaveBeenCalledTimes(1)
+    expect(navigator.clipboard.writeText).toHaveBeenCalledWith(
+      'https://example.com/t/active-4b#k=test',
+    )
+  })
+
   it('shows a retry-focused fallback when clipboard access fails', async () => {
     Object.assign(navigator, {
       clipboard: {
@@ -432,6 +463,43 @@ describe('ShareCard', () => {
     ).not.toBeInTheDocument()
   })
 
+  it('guards copy and share handlers when a transfer has no share link', async () => {
+    render(
+      <MemoryRouter>
+        <ShareCard
+          transfer={createTransfer('active-10', 'Missing share link', '2026-03-21T10:00:00.000Z', {
+            shareUrl: '',
+          })}
+          onExtendTransfer={extendTransferMock}
+        />
+      </MemoryRouter>,
+    )
+
+    await act(async () => {
+      await Promise.resolve()
+    })
+
+    const copyButton = screen.getByRole('button', { name: 'Copy link' }) as HTMLButtonElement
+    const shareButton = screen.getByRole('button', { name: 'Share link' }) as HTMLButtonElement
+
+    expect(copyButton).toBeDisabled()
+    expect(shareButton).toBeDisabled()
+
+    copyButton.disabled = false
+    shareButton.disabled = false
+
+    fireEvent.click(copyButton)
+    fireEvent.click(shareButton)
+
+    await act(async () => {
+      await Promise.resolve()
+    })
+
+    expect(navigator.clipboard.writeText).not.toHaveBeenCalled()
+    expect(toDataUrlMock).not.toHaveBeenCalled()
+    expect(document.querySelector('.qr-placeholder')).not.toBeNull()
+  })
+
   it('keeps the QR placeholder when QR generation fails', async () => {
     toDataUrlMock.mockRejectedValueOnce(new Error('QR failed'))
 
diff --git a/apps/web/src/features/share/ShareCard.tsx b/apps/web/src/features/share/ShareCard.tsx
index 98ffe77..27c45e0 100644
--- a/apps/web/src/features/share/ShareCard.tsx
+++ b/apps/web/src/features/share/ShareCard.tsx
@@ -78,64 +78,61 @@ export function ShareCard({ transfer, onExtendTransfer }: Props) {
   }, [qrShareUrl])
 
   /** copyLink writes the full share URL, including the `#k=` fragment, to the clipboard. */
-  const copyLink = async () => {
-    if (!transfer?.shareUrl || !canShareLink) {
-      return
-    }
-    try {
-      setActionError(undefined)
-      await navigator.clipboard.writeText(transfer.shareUrl)
-      setCopyState('copied')
-      window.setTimeout(() => setCopyState('idle'), 1800)
-    } catch {
-      setCopyState('idle')
-      setActionError('Copy failed. Use your browser share tools or try again on this device.')
-    }
-  }
+  const copyLink = qrShareUrl
+    ? async () => {
+        try {
+          setActionError(undefined)
+          await navigator.clipboard.writeText(qrShareUrl)
+          setCopyState('copied')
+          window.setTimeout(() => setCopyState('idle'), 1800)
+        } catch {
+          setCopyState('idle')
+          setActionError('Copy failed. Use your browser share tools or try again on this device.')
+        }
+      }
+    : undefined
 
   /** shareLink uses the platform share sheet when available and falls back to copying. */
-  const shareLink = async () => {
-    if (!transfer?.shareUrl || !canShareLink) {
-      return
-    }
-    if (navigator.share) {
-      try {
-        setActionError(undefined)
-        await navigator.share({
-          title: transfer.displayName,
-          url: transfer.shareUrl,
-          text: 'Encrypted files via Xdrop',
-        })
-        return
-      } catch (error) {
-        if (isAbortLike(error)) {
-          return
+  const shareLink = qrShareUrl
+    ? async () => {
+        if (navigator.share) {
+          try {
+            setActionError(undefined)
+            await navigator.share({
+              title: transfer?.displayName,
+              url: qrShareUrl,
+              text: 'Encrypted files via Xdrop',
+            })
+            return
+          } catch (error) {
+            if (isAbortLike(error)) {
+              return
+            }
+            await copyLink?.()
+            return
+          }
         }
-        await copyLink()
-        return
+
+        await copyLink?.()
       }
-    }
+    : undefined
 
-    await copyLink()
-  }
-
-  const extendExpiry = async () => {
-    if (!transfer || !canExtendTransfer || !onExtendTransfer) {
-      return
-    }
-
-    try {
-      setActionError(undefined)
-      setIsExtending(true)
-      await onExtendTransfer(transfer.id, MAX_EXPIRY_SECONDS)
-    } catch (error) {
-      setActionError(
-        error instanceof Error ? error.message : 'Could not update this transfer right now.',
-      )
-    } finally {
-      setIsExtending(false)
-    }
-  }
+  const extendExpiry =
+    canExtendTransfer && transfer && onExtendTransfer
+      ? async () => {
+          try {
+            setActionError(undefined)
+            setIsExtending(true)
+            await onExtendTransfer(transfer.id, MAX_EXPIRY_SECONDS)
+          } catch (error) {
+            setActionError(
+              error instanceof Error ? error.message : 'Could not update this transfer right now.',
+            )
+          } finally {
+            setIsExtending(false)
+          }
+        }
+      : undefined
 
   if (!transfer) {
     return (
@@ -229,13 +226,17 @@ export function ShareCard({ transfer, onExtendTransfer }: Props) {
         </dl>
 
         <div className="button-row">
-          <Button onClick={() => void copyLink()} disabled={!canShareLink}>
+          <Button onClick={copyLink ? () => void copyLink() : undefined} disabled={!copyLink}>
             {copyState === 'copied' ? 'Copied' : 'Copy link'}
           </Button>
-          <Button onClick={() => void shareLink()} tone="ghost" disabled={!canShareLink}>
+          <Button
+            onClick={shareLink ? () => void shareLink() : undefined}
+            tone="ghost"
+            disabled={!shareLink}
+          >
             Share link
           </Button>
-          {canExtendTransfer ? (
+          {extendExpiry ? (
             <Button tone="ghost" onClick={() => void extendExpiry()} disabled={isExtending}>
               {isExtending
                 ? 'Updating expiry…'
diff --git a/apps/web/src/features/upload/TransferContext.actions.test.tsx b/apps/web/src/features/upload/TransferContext.actions.test.tsx
index 85e19ce..475761c 100644
--- a/apps/web/src/features/upload/TransferContext.actions.test.tsx
+++ b/apps/web/src/features/upload/TransferContext.actions.test.tsx
@@ -554,4 +554,41 @@ describe('TransferProvider actions', () => {
       ).toBeInTheDocument()
     })
   })
+
+  it('aborts active upload runtimes when deleting a transfer mid-flight', async () => {
+    transfersStore.set('t1', makeTransferRecord('uploading'))
+    sourcesStore.set('t1:file-1', makeSourceRecord('t1'))
+
+    let aborts = 0
+    vi.stubGlobal(
+      'fetch',
+      vi.fn(
+        (_url: string, init?: RequestInit) =>
+          new Promise((_, reject) => {
+            const signal = init?.signal as AbortSignal | undefined
+            signal?.addEventListener('abort', () => {
+              aborts += 1
+              reject(new DOMException('aborted', 'AbortError'))
+            })
+          }),
+      ),
+    )
+
+    renderProvider()
+
+    await waitFor(() => {
+      expect(global.fetch).toHaveBeenCalled()
+    })
+    await waitFor(() => expect(latestContext).not.toBeNull())
+
+    await act(async () => {
+      await latestContext?.deleteTransfer('t1')
+    })
+
+    expect(aborts).toBeGreaterThan(0)
+    expect(deleteRemoteTransferMock).toHaveBeenCalledWith('t1', 'manage-token')
+    expect(deletePersistedTransferSourcesMock).toHaveBeenCalledWith('t1')
+    expect(deleteTransferRecordMock).toHaveBeenCalledWith('t1')
+    expect(transfersStore.has('t1')).toBe(false)
+  })
 })
diff --git a/apps/web/src/features/upload/UploadStudio.test.tsx b/apps/web/src/features/upload/UploadStudio.test.tsx
index 8e3fd0b..1ab39ff 100644
--- a/apps/web/src/features/upload/UploadStudio.test.tsx
+++ b/apps/web/src/features/upload/UploadStudio.test.tsx
@@ -1,4 +1,4 @@
-import { fireEvent, render, screen, waitFor } from '@testing-library/react'
+import { act, fireEvent, render, screen, waitFor } from '@testing-library/react'
 import {
   DEFAULT_EXPIRY_SECONDS,
   EXPIRY_OPTIONS,
@@ -355,6 +355,69 @@ describe('UploadStudio', () => {
     ).toBeInTheDocument()
   })
 
+  it('avoids updating state when draft persistence resolves after unmount', async () => {
+    const persistedFile = new File(['hello'], 'draft.txt', { lastModified: 12, type: 'text/plain' })
+    let resolvePersist: ((sources: typeof draftState.sources) => void) | undefined
+    persistDraftMock.mockImplementationOnce(
+      () =>
+        new Promise((resolve) => {
+          resolvePersist = resolve
+        }),
+    )
+    const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => {})
+
+    const { container, unmount } = renderStudio()
+
+    fireEvent.change(container.querySelector('input[type="file"]') as HTMLInputElement, {
+      target: { files: [persistedFile] },
+    })
+
+    unmount()
+
+    await act(async () => {
+      resolvePersist?.([
+        {
+          draftKey: 'draft-1',
+          file: persistedFile,
+          relativePath: 'draft.txt',
+        },
+      ])
+      await Promise.resolve()
+    })
+
+    expect(errorSpy).not.toHaveBeenCalled()
+    errorSpy.mockRestore()
+  })
+
+  it('avoids surfacing persistence errors after unmount', async () => {
+    let rejectPersist: ((reason?: unknown) => void) | undefined
+    persistDraftMock.mockImplementationOnce(
+      () =>
+        new Promise((_, reject) => {
+          rejectPersist = reject
+        }),
+    )
+    const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => {})
+
+    const { container, unmount } = renderStudio()
+
+    fireEvent.change(container.querySelector('input[type="file"]') as HTMLInputElement, {
+      target: {
+        files: [new File(['hello'], 'draft.txt', { lastModified: 12, type: 'text/plain' })],
+      },
+    })
+
+    unmount()
+
+    await act(async () => {
+      rejectPersist?.(new Error('persist failed'))
+      await Promise.resolve()
+    })
+
+    expect(errorSpy).not.toHaveBeenCalled()
+    errorSpy.mockRestore()
+  })
+
   it('prefers webkitRelativePath over the bare filename when a folder is chosen', async () => {
     const { container } = renderStudio()
     const nestedFile = new File(['folder'], 'nested.txt', { lastModified: 14, type: 'text/plain' })
diff --git a/apps/web/src/features/upload/UploadStudio.tsx b/apps/web/src/features/upload/UploadStudio.tsx
index e22e3e9..a3b0ba6 100644
--- a/apps/web/src/features/upload/UploadStudio.tsx
+++ b/apps/web/src/features/upload/UploadStudio.tsx
@@ -153,12 +153,6 @@ export function UploadStudio() {
 
   /** launchTransfer hands the staged sources to the transfer runtime and navigates to share view. */
   const launchTransfer = async () => {
-    if (selectionLimitError) {
-      setSelectionError(selectionLimitError)
-      setLaunchError(undefined)
-      return
-    }
-
     try {
       setIsLaunching(true)
       setLaunchError(undefined)
diff --git a/apps/web/src/lib/download/zip.test.ts b/apps/web/src/lib/download/zip.test.ts
index cd7daec..4e378ac 100644
--- a/apps/web/src/lib/download/zip.test.ts
+++ b/apps/web/src/lib/download/zip.test.ts
@@ -1,9 +1,18 @@
-import { describe, expect, it } from 'vitest'
+import { afterEach, describe, expect, it } from 'vitest'
 
 import { sanitizePath } from '@/lib/files/paths'
 import { buildBinaryZip, buildTextZip, buildZip, writeZipStream } from './zip'
 
 describe('zip builder', () => {
+  const OriginalResponse = globalThis.Response
+
+  afterEach(() => {
+    Object.defineProperty(globalThis, 'Response', {
+      configurable: true,
+      value: OriginalResponse,
+    })
+  })
+
   it('preserves sanitized folder structure', async () => {
     const zipBlob = await buildZip([
       { path: '../folder/photo.png', blob: new Blob(['a']) },
@@ -101,4 +110,49 @@ describe('zip builder', () => {
     ).resolves.toBeUndefined()
     expect(chunks.length).toBeGreaterThan(0)
   })
+
+  it('uses arrayBuffer-backed blobs when stream() is unavailable', async () => {
+    const blobLike = {
+      arrayBuffer: async () => new TextEncoder().encode('hello').buffer,
+      size: 5,
+      type: 'text/plain',
+    } as unknown as Blob
+
+    const zipBlob = await buildZip([{ path: 'fallback/data.txt', blob: blobLike }])
+
+    expect(zipBlob.type).toBe('application/zip')
+    expect(zipBlob.size).toBeGreaterThan(0)
+  })
+
+  it('falls back to Response bodies when blob helpers are unavailable', async () => {
+    const blobLike = {
+      size: 5,
+      type: 'text/plain',
+    } as unknown as Blob
+
+    const zipBlob = await buildZip([{ path: 'fallback/data.txt', blob: blobLike }])
+
+    expect(zipBlob.type).toBe('application/zip')
+    expect(zipBlob.size).toBeGreaterThan(0)
+  })
+
+  it('throws when no blob streaming strategy is available', async () => {
+    class ResponseWithoutBody {
+      readonly body = null
+    }
+
+    Object.defineProperty(globalThis, 'Response', {
+      configurable: true,
+      value: ResponseWithoutBody,
+    })
+
+    const blobLike = {
+      size: 5,
+      type: 'text/plain',
+    } as unknown as Blob
+
+    await expect(buildZip([{ path: 'fallback/data.txt', blob: blobLike }])).rejects.toThrow(
+      'Blob stream is unavailable.',
+    )
+  })
 })
diff --git a/apps/web/src/lib/files/persistentSources.test.ts b/apps/web/src/lib/files/persistentSources.test.ts
index bb2c19d..1f36eb1 100644
--- a/apps/web/src/lib/files/persistentSources.test.ts
+++ b/apps/web/src/lib/files/persistentSources.test.ts
@@ -137,6 +137,48 @@ describe('persistentSources', () => {
     ).resolves.toBeNull()
   })
 
+  it('returns null when navigator is unavailable or the OPFS root cannot be opened', async () => {
+    const originalNavigator = globalThis.navigator
+
+    Object.defineProperty(globalThis, 'navigator', {
+      configurable: true,
+      value: undefined,
+    })
+
+    await expect(
+      persistSourceToOpfs({
+        file: new File(['hello'], 'draft.txt'),
+        fileId: 'file-1',
+        relativePath: 'draft.txt',
+        transferId: 'transfer-1',
+      }),
+    ).resolves.toBeNull()
+
+    Object.defineProperty(globalThis, 'navigator', {
+      configurable: true,
+      value: originalNavigator,
+    })
+
+    const harness = createOpfsHarness()
+    harness.storage.getDirectory.mockResolvedValueOnce({
+      getDirectoryHandle: vi.fn(async () => {
+        throw new Error('denied')
+      }),
+      getFileHandle: vi.fn(),
+      removeEntry: vi.fn(async () => {}),
+    })
+    stubStorage(harness.storage)
+
+    await expect(
+      persistSourceToOpfs({
+        file: new File(['hello'], 'draft.txt'),
+        fileId: 'file-1',
+        relativePath: 'draft.txt',
+        transferId: 'transfer-1',
+      }),
+    ).resolves.toBeNull()
+  })
+
   it('restores indexeddb-backed files and handles missing files', async () => {
     const file = new File(['payload'], 'example.txt', { type: 'text/plain', lastModified: 5 })
 
diff --git a/apps/web/src/lib/i18n/formatDateTime.test.ts b/apps/web/src/lib/i18n/formatDateTime.test.ts
new file mode 100644
index 0000000..68c48a1
--- /dev/null
+++ b/apps/web/src/lib/i18n/formatDateTime.test.ts
@@ -0,0 +1,76 @@
+import { afterEach, describe, expect, it, vi } from 'vitest'
+
+import { formatLocalDateTime } from './formatDateTime'
+
+const originalNavigator = globalThis.navigator
+
+describe('formatLocalDateTime', () => {
+  afterEach(() => {
+    Object.defineProperty(globalThis, 'navigator', {
+      configurable: true,
+      value: originalNavigator,
+    })
+    vi.restoreAllMocks()
+  })
+
+  it('returns an empty string for invalid date values', () => {
+    expect(formatLocalDateTime('not-a-date')).toBe('')
+  })
+
+  it('prefers navigator.language when navigator.languages is empty', () => {
+    let observedLocales: Intl.LocalesArgument | undefined
+    let observedOptions: Intl.DateTimeFormatOptions | undefined
+    const DateTimeFormatMock = vi
+      .spyOn(Intl, 'DateTimeFormat')
+      .mockImplementation(function (locales?: Intl.LocalesArgument, options?: Intl.DateTimeFormatOptions) {
+        observedLocales = locales
+        observedOptions = options
+        return {
+          format: () => 'formatted',
+        } as Intl.DateTimeFormat
+      })
+
+    Object.defineProperty(globalThis, 'navigator', {
+      configurable: true,
+      value: {
+        language: 'fr-FR',
+        languages: [],
+      },
+    })
+
+    expect(formatLocalDateTime('2026-03-20T10:00:00.000Z')).toBe('formatted')
+    expect(DateTimeFormatMock).toHaveBeenCalledTimes(1)
+    expect(observedLocales).toEqual(['fr-FR'])
+    expect(observedOptions).toMatchObject({
+      dateStyle: 'medium',
+      timeStyle: 'short',
+    })
+  })
+
+  it('falls back to an undefined locale list when navigator is unavailable', () => {
+    let observedLocales: Intl.LocalesArgument | undefined
+    let observedOptions: Intl.DateTimeFormatOptions | undefined
+    const DateTimeFormatMock = vi
+      .spyOn(Intl, 'DateTimeFormat')
+      .mockImplementation(function (locales?: Intl.LocalesArgument, options?: Intl.DateTimeFormatOptions) {
+        observedLocales = locales
+        observedOptions = options
+        return {
+          format: () => 'formatted',
+        } as Intl.DateTimeFormat
+      })
+
+    Object.defineProperty(globalThis, 'navigator', {
+      configurable: true,
+      value: undefined,
+    })
+
+    expect(formatLocalDateTime('2026-03-20T10:00:00.000Z')).toBe('formatted')
+    expect(DateTimeFormatMock).toHaveBeenCalledTimes(1)
+    expect(observedLocales).toBeUndefined()
+    expect(observedOptions).toMatchObject({
+      dateStyle: 'medium',
+      timeStyle: 'short',
+    })
+  })
+})