deb,cli,test,docs: record and show dep-install and build durations

Every binary build measures its dependency installation (apt-get
update, the essential and injected packages, each build-dependency
pass) and its package build (debian/rules build plus binary) into a
timings accumulator; the record manifest stores both as an optional
`timings` field when the run ends, whatever the outcome — a failed
build keeps its partial durations, and a run that died before any
timed command records nothing.

`pkh deb list` shows the two durations as DEPS and BUILD columns,
formatted like the age ("45s", "2m41s", "1h02m"); records predating
the field show dashes. The field is serde-optional, so the manifest
schema stays at 1 and existing records remain discoverable and
forkable.

src/deb/local.rs

@@ -15,6 +15,7 @@ use crate::deb::cross;
 use crate::deb::session;
 use crate::debian::control::ControlInfo;
 use crate::debian::deps::{Deps, Facts, ParseOpts, PkgRelation};
+use std::time::Instant;
 
 /// Attach the capture sink to a command when the live UI is active
 fn cap<'a>(
@@ -106,6 +107,9 @@ pub async fn build(
     session: Option<&session::Session>,
     build_resume: bool,
     ccache: bool,
+    // Accumulator of the measured dependency-installation and build
+    // durations; the caller records it on the build record.
+    timings: &mut session::BuildTimings,
 ) -> Result<Vec<PathBuf>, Box<dyn Error>> {
     let sink: Option<Arc<dyn LineSink>> = view.sink();
 
@@ -261,6 +265,7 @@ pub async fn build(
     // Update package lists
     log::debug!("Updating package lists for local build...");
     enter_phase(view, Phase::UpdatingPackageLists);
+    let started = Instant::now();
     let status = cap(
         ctx.command("apt-get").envs(env.clone()).arg("update"),
         &sink,
@@ -274,6 +279,7 @@ pub async fn build(
             e
         )
     })?;
+    timings.add_deps(started.elapsed());
     if !status.success() {
         return Err("apt-get update failed inside the build context. \
              If this is a local build, try executing with sudo, \
@@ -305,7 +311,9 @@ pub async fn build(
         cmd.arg(format!("libc6-dev:{arch}"));
     }
     enter_phase(view, Phase::InstallingEssentials);
+    let started = Instant::now();
     let status = cap(&mut cmd, &sink).status()?;
+    timings.add_deps(started.elapsed());
     if !status.success() {
         return Err("Could not install essential packages for the build".into());
     }
@@ -348,7 +356,7 @@ pub async fn build(
 
     // Install injected packages if specified
     if !inject_packages.is_empty() {
-        install_injected_packages(inject_packages, &env, ctx.clone(), view, &sink)?;
+        install_injected_packages(inject_packages, &env, ctx.clone(), view, &sink, timings)?;
     }
 
     // Resolve and install the Build-* dependencies with dpkg's cross
@@ -367,6 +375,7 @@ pub async fn build(
         ctx.clone(),
         view,
         &sink,
+        timings,
     )?;
     // (The build-dependency phase reruns in every fresh chroot: nothing
     // to journal.)
@@ -400,6 +409,7 @@ pub async fn build(
     // Run the build step
     log::debug!("Building (debian/rules build) package...");
     enter_phase(view, Phase::Building);
+    let started = Instant::now();
     let status = cap(
         ctx.command("debian/rules")
             .current_dir(package_dir_str)
@@ -408,6 +418,7 @@ pub async fn build(
         &sink,
     )
     .status()?;
+    timings.add_build(started.elapsed());
     if !status.success() {
         return Err("Error while building the package".into());
     }
@@ -428,6 +439,7 @@ pub async fn build(
 
     // Run the 'binary' step to produce deb
     enter_phase(view, Phase::ProducingBinaries);
+    let started = Instant::now();
     let status = cap(
         ctx.command("fakeroot")
             .current_dir(package_dir_str)
@@ -437,6 +449,7 @@ pub async fn build(
         &sink,
     )
     .status()?;
+    timings.add_build(started.elapsed());
     if !status.success() {
         return Err(
             "Error while building the binary artifacts (.deb) from the built package".into(),
@@ -730,6 +743,7 @@ fn install_build_dependencies(
     ctx: Arc<Context>,
     view: &dyn BuildView,
     sink: &Option<Arc<dyn LineSink>>,
+    timings: &mut session::BuildTimings,
 ) -> Result<(), Box<dyn Error>> {
     enter_phase(view, Phase::InstallingBuildDeps);
 
@@ -878,7 +892,9 @@ fn install_build_dependencies(
         for spec in &specs {
             cmd.arg(spec);
         }
+        let started = Instant::now();
         let status = cap(&mut cmd, sink).status()?;
+        timings.add_deps(started.elapsed());
         if !status.success() {
             view.suspend();
             // Diagnosing a dependency failure the user interrupted themselves
@@ -1210,6 +1226,7 @@ pub(crate) fn install_injected_packages(
     ctx: Arc<Context>,
     view: &dyn BuildView,
     sink: &Option<Arc<dyn LineSink>>,
+    timings: &mut session::BuildTimings,
 ) -> Result<(), Box<dyn Error>> {
     log::info!("Installing injected packages: {:?}", packages);
 
@@ -1252,7 +1269,9 @@ pub(crate) fn install_injected_packages(
         if !package_names.is_empty() {
             cmd.args(&package_names);
         }
+        let started = Instant::now();
         let status = cap(&mut cmd, sink).status()?;
+        timings.add_deps(started.elapsed());
         if !status.success() {
             return Err(format!("Could not install injected packages: {:?}", deb_files).into());
         }