feat(causal): ledger-audit output in the pipeline demo and attrib probe

- causal_pipeline: SMARM_CAUSAL_AUDIT=1 appends render_ledger_audit()
  after the summary; pinned summary format untouched.
- causal_attrib_probe: per-pct audit line (absorbed/forgiven/drops/
  discards) under the existing eff line, so in-site-vs-attributed and
  the loss buckets land in one place for the sweep.

1-core smoke (work + wide): books balance — absorbed = 2x injected and
forgiven = 2x injected, i.e. owed = injected x (N-1) with N=5 actors,
zero outstanding. drop park = 0 even in wide mode (the bottleneck's
queue is never empty, so its in-guard recv never parks); drop yield is
~1500 events but ~0.1ms per window, confirming slice-expiry yields
sample at their own checkpoint. Deficit decomposition needs the
parallel box.

.gitignore

@@ -4,3 +4,4 @@ smarm_trace.json
 /bench_results/
 __pycache__/
 *.pyc
+profile.coz

examples/causal_attrib_probe.rs

@@ -136,9 +136,11 @@ fn main() {
             let g0 = smarm::causal::global_delay_cycles();
             let s0 = IN_SITE_CYCLES.load(Ordering::Relaxed);
             let e0 = SITE_ENTRIES.load(Ordering::Relaxed);
+            let a0 = smarm::causal::ledger_counters();
             smarm::causal::begin_experiment_for_test("reserve", pct);
             smarm::sleep(Duration::from_millis(1000));
             smarm::causal::end_experiment_for_test();
+            let audit = smarm::causal::ledger_counters().delta_since(&a0);
             let injected = smarm::causal::global_delay_cycles() - g0;
             let in_site = IN_SITE_CYCLES.load(Ordering::Relaxed) - s0;
             let entries = SITE_ENTRIES.load(Ordering::Relaxed) - e0;
@@ -156,6 +158,22 @@ fn main() {
                 in_site as f64 / hz * 1e3,
                 attributed / hz * 1e3,
             );
+            // RFC 007 deficit hunt: name the losses. Drop/discard columns are
+            // in would-be delta terms — divide by pct/100 to compare with the
+            // missing attribution above.
+            let ms = |c: u64| c as f64 / hz * 1e3;
+            println!(
+                "        audit: absorbed {:>7.1}ms  forgiven {:>6.1}ms  drop park {:>5.2}ms/{:<5} yield {:>5.2}ms/{:<5} discard >max {:>5.2}ms/{:<3} unarmed {}",
+                ms(audit.spin_absorbed_cycles),
+                ms(audit.park_forgiven_cycles),
+                ms(audit.drop_park_cycles),
+                audit.drop_park_n,
+                ms(audit.drop_yield_cycles),
+                audit.drop_yield_n,
+                ms(audit.discard_overmax_cycles),
+                audit.discard_overmax_n,
+                audit.discard_unarmed_n
+            );
             smarm::sleep(Duration::from_millis(150));
         }
 

examples/causal_pipeline.rs

@@ -247,6 +247,12 @@ fn main() {
         background.join().unwrap();
 
         print!("{}", smarm::causal::render_summary(&results));
+        // RFC 007 deficit hunt: SMARM_CAUSAL_AUDIT=1 appends the per-cell
+        // ledger audit (injected/absorbed/forgiven + drop and discard
+        // buckets) without touching the pinned summary format.
+        if std::env::var_os("SMARM_CAUSAL_AUDIT").is_some() {
+            print!("{}", smarm::causal::render_ledger_audit(&results));
+        }
         let coz = smarm::causal::render_coz(&results);
         match std::fs::write("profile.coz", coz) {
             Ok(()) => println!("\nwrote profile.coz"),