fix(observability,settings): the lag event names its real fields and ladders shed duplicates

The wide-event type declared loop_p99_ms while the monitor publishes
loop_last_ms — a dashboard built on the declared field would find
nothing; the type now states what is emitted. Ladder reconciliation
collapses duplicate entries first-occurrence-wins, so a duplicate-laden
ladder written through the API can no longer overflow the schema's
eight-entry cap when the settings page echoes the resolved shape back.

src/lib/logging/event-builder.ts

@@ -137,7 +137,7 @@ export class WideEventBuilder {
     // nicht existiert — der Slot ist dort einfach leer.
     const lag = (
       globalThis as unknown as {
-        [key: symbol]: { loop_max_ms: number; loop_p99_ms: number };
+        [key: symbol]: { loop_max_ms: number; loop_last_ms: number };
       }
     )[Symbol.for("healthlog.eventLoopLag")];
     if (lag) this.event.runtime = lag;

src/lib/logging/types.ts

@@ -95,7 +95,7 @@ export interface WideEvent {
   // den Stall mitfuehrt)
   runtime?: {
     loop_max_ms: number;
-    loop_p99_ms: number;
+    loop_last_ms: number;
   };
 
   // Fehler-Details

src/lib/validations/__tests__/source-priority.test.ts

@@ -457,3 +457,23 @@ describe("parseSourcePriority — stored-ladder reconciliation (v1.16.11)", () =
     expect(resolved.metricPriority.sleep).toContain("WITHINGS");
   });
 });
+
+describe("parseSourcePriority — duplicate tolerance (v1.16.11)", () => {
+  it("collapses duplicates so a resolved ladder can never overflow the schema cap", () => {
+    const resolved = parseSourcePriority({
+      metricPriority: {
+        weight: [
+          "MANUAL",
+          "MANUAL",
+          "WITHINGS",
+          "MANUAL",
+          "WITHINGS",
+        ],
+      },
+    });
+    const ladder = resolved.metricPriority.weight;
+    expect(new Set(ladder).size).toBe(ladder.length);
+    expect(ladder.slice(0, 2)).toEqual(["MANUAL", "WITHINGS"]);
+    expect(ladder.length).toBeLessThanOrEqual(8);
+  });
+});

src/lib/validations/source-priority.ts

@@ -361,7 +361,11 @@ function buildResolved(
   // the old behaviour ranked them (after everything ranked).
   const merged = {} as Required<MetricPriority>;
   for (const key of Object.keys(replaced) as (keyof MetricPriority)[]) {
-    const stored = replaced[key];
+    // First occurrence wins on duplicates — a duplicate-laden ladder
+    // written through the API directly would otherwise grow past the
+    // schema's 8-entry cap once the settings page echoes the resolved
+    // shape back through PUT.
+    const stored = [...new Set(replaced[key])];
     const missing = DEFAULT_SOURCE_PRIORITY[key].filter(
       (source) => !stored.includes(source),
     );