[Bug]: Draw template number fields reject valid decimals (e.g. 1.2 with step 0.1) due to floating-point step check #1129

Checked for duplicates

Yes - I've already checked

Describe the bug

When I save a Draw feature whose property template has a number field with a decimal step (e.g. step: 0.1), many valid values are rejected. Entering 1.2 and pressing Save All Changes shows:

This feature has invalid form values: 'canopy_height_m' must be a multiple of 0.1

and the feature is not saved.

The check in DrawTool_Templater.js (getTemplateValues, the number case; line ~427 on development) compares a floating-point quotient to its integer part:

values[t.field] / t.step != parseInt(values[t.field] / t.step)

In IEEE-754, 1.2 / 0.1 === 11.999999999999998, so parseInt gives 11 and the value is "not a multiple". For step: 0.1, 16 of the 50 values from 0.1 to 5.0 are rejected: 0.3, 0.6, 0.7, 1.2, 1.4, 1.9, 2.3, 2.4, 2.8, 2.9, 3.3, 3.8, 4.1, 4.3, 4.6, 4.8. step: 0.01 is affected the same way.

The user sees a validation error for a correct value and has no way to enter it.

What did you expect?

I expected any value that is a whole number of steps from 0 (to within floating-point tolerance) to be accepted. For example:

const q = values[t.field] / t.step
if (Math.abs(q - Math.round(q)) > 1e-9) invalids[t.field] = `'${t.field}' must be a multiple of ${t.step}`

(Relative to min rather than 0 may also be intended, as in HTML <input step>, but that is a separate question.)

Reproducible steps

1. Give a Draw file a template with: { "type": "number", "field": "h", "label": "Height", "min": 0, "max": 50, "step": 0.1 }
2. Draw a feature in that file and open its properties.
3. Enter 1.2 in Height and press "Save All Changes".
4. Toast: "This feature has invalid form values: 'h' must be a multiple of 0.1". Not saved.
   (1.5 or 1.0 save fine.)

# Quick check of the arithmetic:
node -e 'for(let i=1;i<=50;i++){const v=+(i/10).toFixed(1);if(v/0.1!=parseInt(v/0.1))console.log(v)}'

Environment

- MMGIS: present on `development` (5.3.15-20260825); the comparison dates from the original templates feature (#353)
- Seen on: iPad Pro 13" (2025), iOS 26.4, WKWebView; also reproducible in any browser, as it is pure arithmetic