report: reproduce the pre-refactor CLI output through the ports

Instead of carrying raw UI in core, the ports now represent everything
the CLI used to do inline:

- Prompter::present shows context outside of a question (the wizard
  summary screen, the vendoring notice spacing); TerminalPrompter
  prints it on stdout exactly like the println!s it replaces, server
  embeds forward it as a display event.
- generate_entry returns the generated entry (package, versions,
  series, path) instead of printing; the CLI renders the same lines.
- BuildTarget carries a flow-composed display line and a tee_log flag:
  the terminal adapter renders it verbatim ("Building source package
  ...", "Building ... for series/arch", "Uploading ... to ...") and
  uploads open no build log.
- The unmet build-dependency diagnostics are rendered by the CLI from
  the typed error, in the original order (details, then summary).
- --verbose constructs no live view at all (an idle widget used to
  linger), and the re-vendor offer only logs when it is actually
  asked, so headless runs print the error exactly once.

src/debian/deps.rs

@@ -890,11 +890,7 @@ pub struct UnmetBuildDependencies(pub UnmetReport);
 
 impl std::fmt::Display for UnmetBuildDependencies {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(
-            f,
-            "build dependencies/conflicts unsatisfied; aborting\n{}",
-            self.0.message()
-        )
+        write!(f, "build dependencies/conflicts unsatisfied; aborting")
     }
 }