Make the GUI say what it actually did

[fstubner]

Three result-correctness defects from the independent review, all the same shape: the interface reported something the backend did not do.

1. The command preview claimed five ports and scanned three

buildCommand substituted the GUI's DEFAULT_PORTS placeholder (22,80,443,8080,8443) whenever the Ports field was empty, while execution sent no port list at all and the core fell back to its own default of 22,80,443.

That wrong string is what Ctrl+Shift+C copied, what the History menu recorded, and what was stored with the saved result bundle.

-p is now omitted when the field is empty — which is both accurate and what inspect and sweep in the same function already did.

2. Truncated captures were presented as complete

The core sets packets_truncated on a capture and truncated on a parse. Neither was read anywhere in the GUI.

Opening a 20,000-packet file with the default 1,000 limit showed 1,000 rows under a status bar reading 20000 packets, with nothing saying the view was cut off — and Export CSV then wrote only the loaded rows. The summary now reads 1000 of 20000 packets shown.

3. Three call sites disagreed on which ports an inspect checked

site	expression
rows.ts	ports?.length ? ports : open_ports
columns.ts, summaries.ts	ports ?? open_ports

A backend returning ports: [] with a non-empty open_ports rendered rows from open_ports while the columns came from an empty list — every cell blank. All three now call one inspectPorts helper, keeping the length check: ports is optional for older backends and an empty list carries no more information than a missing one.

Also

Two smaller preview fixes in the same function: the pcap capture branch omitted --json while every other command includes it, and interpolated the BPF filter raw, so a filter containing a quote produced a preview that would not parse if pasted.

Verification

Every new test was confirmed to fail against the previous behaviour:

expected 'netscli scan router.local -p 22,80,44…' to be 'netscli scan router.local --json'
expected '20000 packets' to be '1000 of 20000 packets shown'

The pcap summary cases moved to their own file rather than pushing presentation.test.ts past its size cap — which is the split its transition exception already asked for.

105 GUI tests pass, lint 0 errors, build and file-size guard clean.