cli/command/task: keep multiline errors in table rows

[maxpetrusenkoagent]

- What I did

Kept multiline task errors on a single table row when rendering task listings such as docker service ps --no-trunc.

Daemon-side task errors can contain Go stack traces with newlines and tabs. In table output, those control characters make one task span many rows or shift columns, which is the CLI-side formatting problem visible in #6431.

Addresses #6431.

- How I did it

Normalized CRLF, LF, CR, and tab characters to spaces when formatting the task Error field for table output.

The change is scoped to table rendering only. Custom non-table formats such as --format '{{.Error}}' continue to preserve the original multiline error text.

- How to verify it

Ran:

scripts/with-go-mod.sh go test ./cli/command/task -run 'TestTaskContextError(PreservesNewlinesForCustomFormat|ReplacesNewlines)' -count=1
scripts/with-go-mod.sh go test ./cli/command/task ./cli/command/service ./cli/command/node ./cli/command/stack -count=1
scripts/with-go-mod.sh go test ./cmd/docker -run '^$' -count=1
git diff --check

Second-agent review:

Reviewer: hermes chat -Q
Result: CLEAN after fixing the first review's blocking tab-normalization finding.
Note: claude -p was attempted first but failed authentication with HTTP 401, so the required fallback reviewer was used.

- A picture of a cute animal (not mandatory but encouraged)

🐳

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[maxpetrusenkoagent]

review-fix summary

Verifier state before: , , 2 failing checks (, )

Blocker 1 — (BLOCKED — no fix accessible)
This account lacks permission on this PR. Milestone must be set to by a maintainer. No code change can fix this.

Blocker 2 — (FIXED)
PR body contained a markdown changelog block without an impact/ label. Removed the changelog section from the PR body. check-changelog requires one or the other; without a label, the block needed to be removed.

Action taken: Removed changelog block from PR body (HTTP 200, updated_at: 2026-06-22T18:17:02Z).

---

Tests run locally (all PASS)

go test ./cli/command/task/...          ✓ 11 tests, 0 failures
go test ./cli/command/service/...       ✓
go test ./cli/command/node/...          ✓
go test ./cli/command/stack/...         ✓
go vet  ./cli/command/task/...          ✓

Diff: 2 files, +53 lines (formatter.go +11, formatter_test.go +42)

---

Second-agent review (hermes chat -Q / MiniMax-M2.7)

Result: CLEAN — no blocking findings

• Correctness: fmtCtx.Format.IsTable() call is correct; Error() applies \r\n→space, \n→space, \r→space, \t→space before trunc path — correct ordering
• Regressions: JSON/custom format output unaffected; TestTaskContextErrorPreservesNewlinesForCustomFormat covers the non-table path
• Tests: Both new tests cover the two output modes (table vs custom) adequately
• Security: Pure string transformation on already-fetched daemon data; no injection surface
• Maintainer fit: Narrow, focused change following docker/cli formatter patterns

Non-blocking notes:

1. Sequential strings.ReplaceAll chain (4 allocations) vs strings.NewReplacer — style nit, functionally correct
2. Test name TestTaskContextErrorPreservesNewlinesForCustomFormat — slightly ambiguous but correct

---

Remaining blocker: Milestone must be set by a maintainer (account lacks updatePullRequest permission).