# Add `--print-fio-table` debug flag to `fuj sync`

## Context

The Go port of `fuj sync --dry-run` currently prints only the **new**
transactions — i.e. rows that will be appended to the payments sheet after
deduping against existing Sync IDs (see [sync.go:125-129](../../go/internal/services/banksync/sync.go#L125-L129)).
When debugging Fio sync issues ("why isn't transaction X showing up?",
"is the dedup working?"), there's no way to see what Fio actually
returned versus what got filtered as a duplicate.

This change adds a `--print-fio-table` flag that, **only when combined
with `--dry-run`**, prints an aligned table of every Fio transaction in
the window with each row marked `NEW` (would be appended) or `DUP`
(already in sheet, skipped). The flag is silently ignored without
`--dry-run`, so it can't accidentally fire during a real sync.

## Decisions

- Flag name: `--print-fio-table` (specific, not generic `--verbose`).
- Columns: `DATE | AMOUNT | SENDER | VS | MESSAGE | BANKID | STATUS`,
  with MESSAGE truncated and STATUS = `NEW` / `DUP`.
- Scope: only effective when `--dry-run` is also set.

## Files modified

- [go/cmd/fuj/main.go](../../go/cmd/fuj/main.go) — new flag + SyncOpts field
- [go/internal/services/banksync/sync.go](../../go/internal/services/banksync/sync.go) — SyncOpts struct + refactored step 4
- [go/internal/services/banksync/debug.go](../../go/internal/services/banksync/debug.go) — printFioTable helper (new)