Guided prompts: bare "?" has no label, and there is no recall of previous answers

[LukasWodka]

Two related papercuts in the guided ingest flow, both raised from a real session.

1. The prompt line is a bare ?

The guided flow builds its prompter as surveyPrompter{bare: true}, and bare makes the survey message empty:

func (s surveyPrompter) message(label string) string {
	if s.bare { return "" }
	return label
}

So the line renders as ? plus whatever you type. The intent was sound — the CLI already prints the question as a Step 3 of 4 · Where is your data? header, and repeating it on the prompt line would duplicate it.

The cost is a label-less prompt, and the codebase already contradicts itself on this: Confirm is deliberately never bare, with the comment "a bare ? (y/N) there would be a label-less destructive prompt". The same objection applies to the others, and it gets worse now that answers are pre-filled — ? [~/mydata] is a question mark, a bracket and a path, with no verb.

Proposed: give each guided prompt a short noun label — ? Path:, ? Name:, ? Split:, ? Task:. Context without duplication.

Not free: the prompter fake keys scripted answers by label, so this rekeys roughly 50 assertions across interactive_test.go, copy_catalog_test.go and path_examples_test.go, plus a golden regen. Kept out of the always-ask change deliberately so the behaviour diff stayed reviewable.

2. Arrow-up does not recall previous answers

Reported as: "usually when you use a terminal and use the arrow keys up and down it shows past commands, but it doesn't for the ones we are doing… if I re-run through the same process and have to manually type everything in again, it annoys me."

This is expected, not a regression: ↑ is the shell's history. Once the CLI takes the terminal in raw mode the keystroke is ours, and survey's Input has no history — KeyArrowUp/KeyArrowDown are handled only while a suggestion list is open.

Two things survey already gives us:

• Default — now used, so anything passed on the command line is pre-filled (#711).
• Suggest func(toComplete string) []string — Tab completion. Wiring it to the filesystem for the path prompt would make Tab complete paths, and ↑/↓ would then navigate the suggestions.

Proposed, in order of value:

1. Remember the previous run's answers and offer them as defaults, so the default chain is: command-line value → last run → the flow's own fallback. This is what actually answers the complaint — re-running the same ingest becomes four Enters.
2. Tab completion for the path prompt via Suggest.

(1) needs a home for the state. internal/config is env-scoped profiles holding tokens at mode 0600 with a versioned schema and migration — mixing remembered answers into the credential file is the wrong shape. A small separate state file under ~/.tracebloc is likely better, and it should be wiped by tracebloc delete like the rest.

Neither is urgent; both are small and directly improve repeat use.