fix: lazily initialize canvas element in ProgressGauge service

[Kunal1522]

Fixes #90

gaugeService.js called document.getElementById('activeProgress') at factory creation time — before Angular's router rendered the view containing that element. This caused a TypeError: Cannot read properties of null (reading 'getContext') crash.

Fix

Introduced a getCanvas() helper that initializes aProgress and barCTX on first use. All public functions call getCanvas() before accessing the canvas.

-  var aProgress = document.getElementById('activeProgress');
-  var barCTX = aProgress.getContext("2d");
+  var aProgress = null;
+  var barCTX = null;
+
+  function getCanvas() {
+    if (aProgress.getContext('2d') with a TypeError.) {
+      aProgress = document.getElementById('activeProgress');
+      barCTX = aProgress.getContext('2d');
+    }
+  }

By the time any of the public functions (create, reset, progress) are called from the controller, Angular has already rendered the view and #activeProgress exists in the DOM.

Testing

Verified by reviewing call sites in measure.js — ProgressGauge.create() is called inside the controller after Angular bootstraps, ensuring the element is present.

[robertodauria]

Thanks for the contribution. Closing this as it is superseded by #83, which rewrites the codebase removing Angular, jQuery, Gulp, and the old app/ directory structure. The files modified by this PR either no longer exist after that change or the change has already been made.

We aim to merge #83 next week, which will give contributors a stable, modern base to work from. Thoughtful, targeted contributions that build on where the project is heading are much more valuable. We'd encourage you to review #83 and open any future PRs on top of that.