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/report.rs

@@ -30,18 +30,28 @@ pub type Validator = dyn Fn(&str) -> Result<(), String>;
 
 /// Identity of the build whose events follow, as announced through
 /// [`BuildView::target`].
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone)]
 pub struct BuildTarget<'a> {
     /// Source package name (e.g. `hello`).
     pub package: &'a str,
     /// Full version being built (e.g. `2.10-3`).
     pub version: &'a str,
     /// What the build targets: a distribution series, optionally with an
-    /// architecture (`noble`, `sid`, `noble/arm64`).
+    /// architecture (`noble`, `sid`, `noble/arm64`), or the upload target
+    /// label.
     pub target: &'a str,
-    /// Whether this is a source-only build (producing a `.dsc`) as opposed
-    /// to a binary build (producing `.deb` files).
+    /// Ready-to-render status line for display adapters, composed by the
+    /// flow (e.g. "Building source package hello (2.10-3) for unstable",
+    /// "Uploading hello (2.10-3) to ppa:user/ppa"): the wording is the
+    /// flow's, adapters render it verbatim.
+    pub display: String,
+    /// Whether this is a source-only build (producing a `.dsc`); names the
+    /// terminal adapter's tee log (`build-*.log` vs `deb-*.log`).
     pub source_only: bool,
+    /// Whether the view should tee raw subprocess output to its log file.
+    /// Flows without subprocess output (uploads) pass `false` and create
+    /// no log file.
+    pub tee_log: bool,
 }
 
 /// Observer of a running build: target identification, phases, status
@@ -156,6 +166,15 @@ pub trait Prompter: Send + Sync {
     fn accept_host_key(&self, _host: &str, _key_type: &str, _fingerprint: &str) -> bool {
         false
     }
+
+    /// Present information to the user outside of any question: the
+    /// scaffold wizard's summary screen, prominent notices around a
+    /// warning. Terminal implementations print the text as-is (unstyled,
+    /// on stdout); server implementations forward it as a display event.
+    /// Implementations that cannot show anything drop it — flows only
+    /// present context that is also available structurally (returned data,
+    /// log records).
+    fn present(&self, _text: &str) {}
 }
 
 /// Inert view and prompter: drops every event and answers every question