cable-sizing: size for the protective device, not just the load; manual entry; icon position

- calculateCableSizing now selects cross-section against
  designCurrentA = max(operatingCurrentA, existingProtectionRatedCurrentA)
  instead of the load current alone. A breaker only trips at its own rated
  current (In), so a cable sized for the actual load could overheat under
  sustained current below that threshold - the standard In <= Iz rule.
  Voltage-drop calculation still uses the real operating current, only the
  capacity check changed. Alerts and the ok-summary now name the breaker as
  the limiting factor when it is one.
- Added a manual cable type/cross-section entry in the modal itself:
  running a calculation pre-fills these fields as a suggestion, but they
  are the single field that actually gets applied, and stay editable -
  this restores the direct manual-entry capability the modal replaced when
  it took over the cableSummary/cableCrossSection cell click.
- Fixed calculator icon position from a trailing ::after (inconsistent
  position depending on cell text length, easy to miss on empty cells) to
  a fixed-position ::before, so it is always in the same place regardless
  of whether cable data is already filled in.
- No new display for the existing protection device - it already has its
  own Schutz column in this app.

tests/cable-sizing-calculation.test.ts

@@ -84,19 +84,43 @@ describe("calculateCableSizing", () => {
     assert.equal(singlePhaseWithHarmonics.harmonicReductionApplied, false);
   });
 
-  it("flags a simplified protection coordination mismatch", () => {
+  it("uses max(operatingCurrentA, existingProtectionRatedCurrentA) as the design current for cross-section selection", () => {
+    // Load alone (21.7 A) would recommend 4 mm² (see the reference case
+    // above); a 32 A breaker on the same circuit must still be covered by
+    // the cable (In <= Iz), so the recommendation should grow accordingly.
+    const withoutBreaker = calculateCableSizing(BASE_INPUT);
+    const withBreaker = calculateCableSizing({
+      ...BASE_INPUT,
+      existingProtectionRatedCurrentA: 32,
+    });
+    assert.equal(withoutBreaker.designCurrentA, withoutBreaker.operatingCurrentA);
+    assert.equal(withBreaker.designCurrentA, 32);
+    assert.ok(
+      (withBreaker.recommendedCrossSectionMm2 ?? 0) >=
+        (withoutBreaker.recommendedCrossSectionMm2 ?? 0)
+    );
+    assert.ok(withBreaker.protectionCoordination?.coordinated);
+  });
+
+  it("reports an oversized breaker as the limiting factor when no cross-section can cover it", () => {
     const result = calculateCableSizing({
       ...BASE_INPUT,
       existingProtectionRatedCurrentA: 1000,
     });
-    assert.ok(result.protectionCoordination);
-    assert.equal(result.protectionCoordination?.coordinated, false);
+    assert.equal(result.designCurrentA, 1000);
+    assert.equal(result.recommendedCrossSectionMm2, null);
+    // No cross-section satisfies the design current at all, so there is no
+    // "recommended but under-protected" case to flag - protectionCoordination
+    // is only meaningful once a recommendation exists.
+    assert.equal(result.protectionCoordination, null);
 
     const alerts = buildCableSizingAlerts(
       { ...BASE_INPUT, existingProtectionRatedCurrentA: 1000 },
       result
     );
-    assert.ok(alerts.some((alert) => alert.text.includes("Koordination prüfen")));
+    assert.equal(alerts.length, 1);
+    assert.equal(alerts[0].kind, "critical");
+    assert.ok(alerts[0].text.includes("Vorhandene Sicherung"));
   });
 });