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/new/questions.rs

@@ -541,7 +541,7 @@ async fn run_wizard(
 
     // Summary screen + final confirmation: Ctrl+C or 'n' abort with
     // nothing written (generation is all-or-nothing later anyway).
-    log::info!("{}", summary_text(&opts, toolchain_pin.as_deref()));
+    prompter.present(&summary_text(&opts, toolchain_pin.as_deref()));
     if !prompter.confirm("Generate?", true)? {
         return Err("Aborted: nothing was written to disk.".into());
     }
@@ -575,6 +575,9 @@ pub async fn offer_verification(
     };
 
     if outcome.vendoring_failed {
+        // Set apart from the surrounding success output by blank lines: a
+        // single warning between two success lines is easy to miss.
+        prompter.present("");
         log::warn!(
             "The Cargo dependencies could NOT be vendored: this package will \
              not build until the vendoring is completed by hand:\n\
@@ -582,6 +585,7 @@ pub async fn offer_verification(
              \x20 2. add the printed source replacement to .cargo/config.toml, \
              plus `[net] offline = true`"
         );
+        prompter.present("");
     }
 
     if no_verify || !prompter.interactive() {