xml: make -q honor TableMapping when -n is not set

[kroexov]

Summary

• -q help promises it is ignored only when --namespaces (-n) is set, but the generator collapsed both Packages sources — explicit -n and implicit TableMapping from the mfd file — into a single nil check. On any real project (where TableMapping is populated) -q new therefore never prompted, making the flag effectively equivalent to -q all.
• Split the two sources: options.Packages now strictly means "from -n"; TableMapping is consulted separately and combined with --quiet mode. Behaviour matrix after the fix:
  • -n set → -q is ignored (help contract), strict mapping, skip the rest.
  • -q all without -n → use TableMapping / existing entities, skip unmapped tables.
  • -q new without -n → use TableMapping / existing entities, prompt for the rest.
  • default → prompt for everything.
• Table selection for the DB read is adjusted so that -q new/default without -t reads public.* (otherwise the prompt path could never trigger when TableMapping was non-empty).

Test plan

• make db-test
• go test -count=1 ./... — all packages pass, including existing TestGenerator_Generate.
• New TestGenerator_QuietWithTableMapping covers three scenarios:
  • -q new + TableMapping{portal:news,categories,tags} → mapped tables are silent, new tables (vfsFiles, countries, …) go through the prompt and land in other.
  • -q all + TableMapping{card:encryptionKeys} (with -t public.encryptionKeys,public.vfsFolders) → no prompt, vfsFolders is skipped.
  • -n custom:encryptionKeys + -q new + TableMapping{portal:encryptionKeys} → -n wins, portal namespace is not created.

Notes

• Minimal API surface added for tests: a private promptNS field on Generator that overrides PromptNS. Reason: promptui.SelectWithAdd needs a real TTY; testing it without injection would require a PTY harness (e.g. go-expect) and Unix-only test infra. Happy to switch to that approach if preferred.