diff --git a/.claude/refactor/CONTRACTS.md b/.claude/refactor/CONTRACTS.md
index 54277a1..45b7dc2 100644
--- a/.claude/refactor/CONTRACTS.md
+++ b/.claude/refactor/CONTRACTS.md
@@ -233,12 +233,17 @@ class PumpingStation extends BaseDomain {
   }
 
   // What the Node-RED status badge shows — see section 7.
+  // Aggregators (no clean state machine) use compose. State-machine
+  // nodes (rotatingMachine) use byState. Both return {fill, shape, text}.
   getStatusBadge() {
-    return statusBadge.fromState({
-      direction: this.flowAggregator.direction,
-      vol:       this.measurements.type('volume').variant('measured').position('atequipment').getCurrentValue('m3'),
-      maxVol:    this.basin.maxVolAtOverflow,
-    });
+    const direction = this.flowAggregator.direction;
+    const vol = this.measurements.type('volume').variant('measured').position('atequipment').getCurrentValue('m3');
+    const pct = (vol / this.basin.maxVolAtOverflow * 100).toFixed(1);
+    const arrow = direction === 'filling' ? '⬆️' : direction === 'draining' ? '⬇️' : '⏸️';
+    return statusBadge.compose([
+      `${arrow} ${pct}%`,
+      `V=${vol.toFixed(2)}/${this.basin.maxVolAtOverflow.toFixed(2)} m³`,
+    ]);
   }
 }
 
diff --git a/.claude/refactor/OPEN_QUESTIONS.md b/.claude/refactor/OPEN_QUESTIONS.md
index 2670695..0df15f6 100644
--- a/.claude/refactor/OPEN_QUESTIONS.md
+++ b/.claude/refactor/OPEN_QUESTIONS.md
@@ -97,3 +97,65 @@ serialisation uses `LatestWinsGate` internally.
 See `CONTRACTS.md §2` for the BaseNodeAdapter shape.
 
 ---
+
+## 2026-05-10 — ChildRouter wildcard subscriptions monkey-patch `emit`
+
+**Context:** P1.2 implementation. EventEmitter has no native wildcard.
+Subscriptions with a partial filter (`{type}`-only or `{position}`-only)
+install a per-variant `emit` proxy on the child's emitter; concrete
+`{type, position}` filters use plain `emitter.on`.
+
+**Question:** Multi-parent children. `child.parent` is already an array
+in `childRegistrationUtils`, so a child can be registered under several
+parents. If two parents each install ChildRouter wildcard proxies on
+the same `child.measurements.emitter`, the wraps stack — but
+`tearDown` only unwraps when its own bookkeeping is empty. Is this
+correct semantics for multi-parent teardown ordering? Or should we
+switch to per-listener fan-out (subscribe to every known
+`<type>.<variant>.<position>` enumerated from a registry)?
+
+**Default chosen:** Stacked wrappers. The current `childRegistrationUtils`
+multi-parent path is rarely exercised in production. Revisit if
+Phase 2 / Phase 4 hits a real multi-parent case.
+
+**Decision needed by:** Phase 4.
+
+---
+
+## 2026-05-10 — `predictionHealth` migration in rotatingMachine
+
+**Context:** P1.4 implementation flagged that the existing
+`rotatingMachine.predictionHealth` carries `quality` (string) +
+`confidence` (0..1 numeric) on top of the new `HealthStatus` shape's
+`{level, flags, message, source}`.
+
+**Question:** Where does `confidence` live after migration?
+
+**Default chosen:** Keep `confidence` on the per-metric drift
+container as a sibling to a `health: HealthStatus` field. Drift
+diagnostics (`nrmse`, `longTermNRMSD`, `immediateLevel`) stay as
+siblings too. `HealthStatus` carries only the standardised five fields.
+
+**Decision needed by:** Phase 5 (`rotatingMachine` refactor).
+
+---
+
+## 2026-05-10 — `dashboardAPI` basic test broken (pre-existing)
+
+**Context:** P1.12 sanity gate. `dashboardAPI/test/basic/structure-module-load.basic.test.js` uses Mocha-style `describe()` globals which don't exist under `node:test`. Reports 0 pass / 1 fail with `ReferenceError: describe is not defined`.
+
+**Action:** Pre-existing — not caused by Phase 1. Convert to `node:test` form during Phase 6 when `dashboardAPI` gets its skeleton refactor. Tracked here so it isn't lost.
+
+---
+
+## 2026-05-10 — `reactor` test runtime is mathjs-bound (pre-existing)
+
+**Context:** P1.12 sanity gate. Every reactor test file takes ~13 s because `require('mathjs')` alone is ~12.5 s on this machine (mathjs is huge and loads its full operator set eagerly). With basic tests parallelised by `node --test`, each subprocess pays the cost. A 90 s outer timeout doesn't accommodate the parallel load.
+
+**Action:** Pre-existing — not caused by Phase 1. Two options to track for Phase 5/6 cleanup:
+1. Switch to a tree-shaken mathjs subset (only ops actually used).
+2. Cache the mathjs instance at module top and pass into Reactor classes.
+
+Tracked; not blocking the refactor.
+
+---