feat(v1.4.0): CSV/Excel/JSON/NextUp exports + hybrid smart year standing

- Export modules (export-csv/json/xlsx) mirroring the PDF layout, plus a
  Next Up import CSV matching the raycast/nextup column contract.
- Hybrid Year Level: View Grades history (exact per-semester standing),
  falling back to units math (prospectus total - lacking), then profile.
  Popup adds a year-mode setting (auto/custom/off).
- On-page button row now offers PDF / CSV / Excel / JSON / Next Up.
- Bump version to 1.4.0.
- Tag-only build workflow with an optional AMO sign step for a signed .xpi;
  separate ci.yml keeps tests on pushes/PRs.
- Tests: year-standing parser tests + export tests (CSV quoting, JSON schema,
  XLSX structure); CI validates XLSX via openpyxl.

export-json.js

@@ -0,0 +1,45 @@
+(function (root, factory) {
+  if (typeof module === 'object' && module.exports) {
+    module.exports = factory();
+  } else {
+    root.ISMIStools = Object.assign(root.ISMIStools || {}, factory());
+  }
+})(typeof self !== 'undefined' ? self : this, function () {
+  'use strict';
+
+  // Build a clean, reusable JSON representation of the study load.
+  // data: { header, courses, totalUnits, year, period }
+  function buildStudyLoadJson(data) {
+    const header = data.header || {};
+    const courses = (data.courses || []).map((c) => ({
+      group: c.group || '',
+      courseCode: c.courseCode || '',
+      description: c.description || '',
+      schedule: c.schedule || '',
+      faculty: (c.faculty || c.teacher) || '',
+      units: c.units || '',
+      status: c.status || ''
+    }));
+    return {
+      meta: {
+        program: header.program || '',
+        studentName: header.fullName || header.studentName || '',
+        studentId: header.studentId || '',
+        academicYear: data.year ? String(data.year) : '',
+        semester: header.semester || data.period || '',
+        yearLevel: header.yearLevel || '',
+        totalUnits: data.totalUnits || '',
+        generatedAt: new Date().toISOString(),
+        extensionVersion: data.extensionVersion || ''
+      },
+      courses,
+      totals: {
+        // A study load lists the courses the student is enrolled in for the
+        // term; there is no "completed" concept here.
+        enrolledUnits: data.totalUnits || ''
+      }
+    };
+  }
+
+  return { buildStudyLoadJson };
+});