Replaces the seven-file `companion/smoke/` directory (Probe trait +
ProbeAttempt + ProbeOutcome + ProbeFailure + ProbeName + RetryPolicy +
run_probe + SmokeSuite + SmokeStage + SmokeReport + SmokeTest +
SmokeAssemblyError, ~1500 LOC) with a single `companion/smoke.rs`.

Net delta: +638 / -1578.

The earlier draft was cardinality matching gone overboard. For what
is, in the end, "after deploy, run an async function and surface a
pipeline report", we now ship:

* `SmokeTest<T>` trait — one async method `verify(&T) -> SmokeReport`.
  Implementers write a regular async fn; no probe abstraction to
  learn, no suite builder, no policy value type.
* `SmokeReport { checks: Vec<CheckReport> }` — the pipeline data the
  dashboard renders top-to-bottom. A report passes iff it has at
  least one check AND every check passed (a smoke impl that forgets
  to push checks fails loudly, not silently).
* `CheckReport { name, passed, detail }` + `pass / pass_with / fail`
  constructors.
* `poll_until` and `tcp_reachable` — free functions, not traits.
  Implementers call them inside `verify` when useful. A future
  `http_healthy` or `k8s_pod_ready` lives in this file as another
  `async fn -> CheckReport`, not as another trait impl.
* `deploy` / `deploy_with_smoke` — free functions, returning
  `DeployOutcome { interpret, smoke }`. `deploy_with_smoke` blocks
  the deploy on smoke success (ADR-023 P4).

Per the PR #292 review: the SmokeTest's associated type is now
`type Interpret: Interpret<T>` (was `type Score: Score<T>`). One
smoke impl can cover every Score that shares an Interpret —
HelmChartScore + NatsHelmChartScore both verified by one
HelmChartSmokeTest. Pairing is convention-only in v0.3 because
`Score::create_interpret` still returns `Box<dyn Interpret<T>>`;
closing the loop is an additive `type Interpret` on `Score`, deferred.

Tests (12 in this module):
- deploy runs interpret and returns the underlying Outcome
- deploy_with_smoke runs smoke only after interpret succeeds
- deploy_with_smoke returns SmokeFailed (with interpret preserved)
  when any check fails
- deploy_with_smoke rejects an empty report — no silent pass-through
- deploy_with_smoke skips smoke entirely when interpret fails
- SmokeReport::passed semantics (nonempty + all pass)
- poll_until pass-on-success, fail-on-budget
- tcp_reachable pass against a real loopback listener
- tcp_reachable fail with timeout against TEST-NET-1

@@ -0,0 +82,4 @@
+    async fn verify(&self, topology: &T) -> SmokeReport;
+}
+
+/// Aggregated smoke result. Dashboards render `checks` top-to-bottom.

@@ -0,0 +138,4 @@
+        }
+    }
+
+    pub fn fail(name: &'static str, detail: impl Into<String>) -> Self {