feat(canvas): resistors default to vertical on add

Every resistor variant ('resistor' + 'resistor-<value>') now lands on
the canvas rotated 90 degrees: reads better, takes less horizontal
space, and drops straight into breadboard columns. Explicit rotations
in metadata defaults are respected. The breadboard auto-vertical drag
check widens from the two-entry set to the same prefix predicate, so
preconfigured variants (resistor-330 etc.) rotate on the board too.

frontend/src/components/DynamicComponent.tsx

@@ -746,11 +746,20 @@ export function createComponentFromMetadata(
   // dark LED). Also strip '-' from metadata.id (e.g. 'led-bar-graph') so
   // the prefix doesn't reintroduce a hyphen.
   const safePrefix = metadata.id.replace(/-/g, '_');
+  const properties: Record<string, any> = { ...metadata.defaultValues };
+  // Resistors default to vertical: they read better, take less horizontal
+  // space, and drop straight into breadboard columns (their pin span
+  // bridges the center trench). Covers 'resistor' and every preconfigured
+  // 'resistor-<value>' variant; anything with an explicit rotation in its
+  // metadata defaults keeps it.
+  if (metadata.id.startsWith('resistor') && properties.rotation === undefined) {
+    properties.rotation = 90;
+  }
   return {
     id: `${safePrefix}_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`,
     metadataId: metadata.id,
     x,
     y,
-    properties: { ...metadata.defaultValues },
+    properties,
   };
 }

frontend/src/components/simulator/SimulatorCanvas.tsx

@@ -30,7 +30,7 @@ import { calculatePinPosition } from '../../utils/pinPositionCalculator';
 import { isBoardComponent, boardPinToNumber } from '../../utils/boardPinMapping';
 import { autoWireColor, WIRE_KEY_COLORS, expandOrthogonalPoints } from '../../utils/wireUtils';
 import {
-  AUTO_VERTICAL_PARTS,
+  isAutoVerticalPart,
   isOverBreadboard,
   snapPositionToBreadboard,
 } from '../../utils/breadboardSnap';
@@ -832,7 +832,7 @@ export const SimulatorCanvas = ({ headerSlot }: SimulatorCanvasProps = {}) => {
           );
           if (dragged) {
             if (
-              AUTO_VERTICAL_PARTS.has(dragged.metadataId) &&
+              isAutoVerticalPart(dragged.metadataId) &&
               (Number(dragged.properties?.rotation) || 0) === 0 &&
               isOverBreadboard(dragged, nx, ny, simState.components)
             ) {
@@ -1424,7 +1424,7 @@ export const SimulatorCanvas = ({ headerSlot }: SimulatorCanvasProps = {}) => {
           // Axial parts entering a breadboard flip to vertical so they
           // bridge the trench columns like on a real board.
           if (
-            AUTO_VERTICAL_PARTS.has(dragged.metadataId) &&
+            isAutoVerticalPart(dragged.metadataId) &&
             (Number(dragged.properties?.rotation) || 0) === 0 &&
             isOverBreadboard(dragged, nx, ny, simState.components)
           ) {

frontend/src/utils/breadboardSnap.ts

@@ -218,5 +218,8 @@ export function isOverBreadboard(
   return false;
 }
 
-/** Axial 2-pin parts that read better vertical on a breadboard. */
+/** Axial 2-pin parts that read better vertical on a breadboard: 'resistor'
-export const AUTO_VERTICAL_PARTS = new Set(['resistor', 'wokwi-resistor']);
+ * plus every preconfigured 'resistor-<value>' variant. */
+export function isAutoVerticalPart(metadataId: string): boolean {
+  return metadataId.startsWith('resistor') || metadataId.startsWith('wokwi-resistor');
+}