feat(web): make stepper values tappable for direct number input

Tap the number to type a value directly instead of clicking +/- repeatedly.
Input auto-selects, commits on Enter/blur, cancels on Escape, and clamps
to min/max constraints.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/src/components/ui/NumericStepper.tsx

@@ -1,3 +1,5 @@
+import { useState, useRef, useEffect } from 'react';
+
 interface Props {
   label: string;
   value: number;
@@ -8,6 +10,17 @@ interface Props {
 }
 
 export default function NumericStepper({ label, value, onChange, min = 0, max, step = 1 }: Props) {
+  const [editing, setEditing] = useState(false);
+  const [editValue, setEditValue] = useState('');
+  const inputRef = useRef<HTMLInputElement | null>(null);
+
+  useEffect(() => {
+    if (editing && inputRef.current) {
+      inputRef.current.focus();
+      inputRef.current.select();
+    }
+  }, [editing]);
+
   const decrement = () => {
     const next = value - step;
     onChange(min !== undefined ? Math.max(min, next) : next);
@@ -18,6 +31,26 @@ export default function NumericStepper({ label, value, onChange, min = 0, max, s
     onChange(max !== undefined ? Math.min(max, next) : next);
   };
 
+  const startEditing = () => {
+    setEditValue(String(value));
+    setEditing(true);
+  };
+
+  const commitEdit = () => {
+    setEditing(false);
+    const parsed = parseInt(editValue, 10);
+    if (isNaN(parsed)) return; // discard invalid input
+    let clamped = parsed;
+    if (min !== undefined) clamped = Math.max(min, clamped);
+    if (max !== undefined) clamped = Math.min(max, clamped);
+    if (clamped !== value) onChange(clamped);
+  };
+
+  const handleKeyDown = (e: React.KeyboardEvent) => {
+    if (e.key === 'Enter') commitEdit();
+    if (e.key === 'Escape') setEditing(false);
+  };
+
   return (
     <div className="stepper">
       <span className="stepper-label">{label}</span>
@@ -30,7 +63,23 @@ export default function NumericStepper({ label, value, onChange, min = 0, max, s
         >
           -
         </button>
-        <span className="stepper-value">{value}</span>
+        {editing ? (
+          <input
+            ref={inputRef}
+            type="number"
+            className="stepper-input"
+            value={editValue}
+            onChange={(e) => setEditValue(e.target.value)}
+            onBlur={commitEdit}
+            onKeyDown={handleKeyDown}
+            min={min}
+            max={max}
+          />
+        ) : (
+          <span className="stepper-value" onClick={startEditing}>
+            {value}
+          </span>
+        )}
         <button
           type="button"
           className="stepper-btn"

web/src/index.css

@@ -362,6 +362,23 @@ button:disabled {
   text-align: center;
   font-weight: 600;
   font-size: 1.1rem;
+  cursor: pointer;
+  border-bottom: 1px dashed var(--color-text-muted);
+  padding: 2px 4px;
+  border-radius: 2px;
+}
+
+.stepper-value:hover {
+  background: var(--color-surface-hover);
+}
+
+.stepper-input {
+  width: 60px;
+  text-align: center;
+  font-weight: 600;
+  font-size: 1.1rem;
+  padding: 2px 4px;
+  height: 30px;
 }
 
 /* Dropdown */