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.

content.js

@@ -141,9 +141,69 @@
       ? selectedPeriod + ' ' + selectedYear
       : (header.semester || '');
 
+    // Resolve the Year Level for the PRINTED semester (hybrid, see design
+    // spec): custom setting wins; else View Grades history matching; else the
+    // units math; else the profile-scraped value.
+    header.yearLevel = await resolveYearLevel(header, selectedPeriod, selectedYear);
+
     return { header, courses, period: selectedPeriod, year: selectedYear };
   }
 
+  // Fetch a same-origin page and return its text, or null on failure.
+  async function fetchText(path) {
+    try {
+      const resp = await fetch(path, { credentials: 'same-origin' });
+      if (!resp.ok) return null;
+      return await resp.text();
+    } catch (e) {
+      return null;
+    }
+  }
+
+  // Hybrid year-level resolution. Returns null only if every source failed.
+  // mode: 'auto' (default) runs the full hybrid; 'custom' uses only the custom
+  // value; 'off' uses only the profile-scraped value.
+  async function resolveYearLevel(header, period, year) {
+    const settings = await browser.storage.local.get(['yearMode', 'customYearLevel']);
+    const mode = settings.yearMode || 'auto';
+    const custom = String(settings.customYearLevel || '').trim();
+
+    if (mode === 'off') {
+      return header.yearLevel ? String(header.yearLevel) : null;
+    }
+    if (mode === 'custom') {
+      return custom ? custom : null;
+    }
+    // auto: custom value wins, then the hybrid sources.
+    if (custom) return custom;
+
+    const yearNum = parseInt(year, 10);
+
+    // 1. View Grades history matching.
+    const gradesHtml = await fetchText('/ViewGrades');
+    if (gradesHtml) {
+      const history = ISMIStools.parseGradeHistory(gradesHtml);
+      const level = ISMIStools.yearLevelForSemester(history, yearNum);
+      if (level != null) return String(level);
+    }
+
+    // 2. Units math: prospectus total minus lacking units.
+    const [prospectusHtml, lackingHtml] = await Promise.all([
+      fetchText('/prospectus/StudentProspectus'),
+      fetchText('/Extras/ViewLackingSubjectsStudent1')
+    ]);
+    if (prospectusHtml) {
+      const yearUnits = ISMIStools.parseProspectusYearUnits(prospectusHtml);
+      const lacking = lackingHtml ? ISMIStools.parseLackingSubjectsUnits(lackingHtml) : 0;
+      const level = ISMIStools.computeYearStandingFromUnits(yearUnits, lacking);
+      if (level != null) return String(level);
+    }
+
+    // 3. Profile-scraped value as a last resort.
+    if (header.yearLevel) return String(header.yearLevel);
+    return null;
+  }
+
   // ---- On-page Download PDF button ----
   const BTN_ID = 'ismisHelperDownloadBtn';
 
@@ -169,22 +229,12 @@
     try {
       btn.disabled = true;
       btn.innerHTML = '<i class="fa fa-spinner fa-spin"></i> Downloading...';
-      const { header, courses, period: selectedPeriod } = await scrapeStudyLoad();
+      const { header, courses } = await scrapeStudyLoad();
       const included = ISMIStools.filterStudyLoadCourses(courses);
       if (!included.length) throw new Error('No enrolled courses found.');
       const totalUnits = ISMIStools.sumUnits(included);
-      const settings = await browser.storage.local.get(['truncateDescription', 'showYearLevel', 'customYearLevel']);
-      // Resolve the Year Level: custom value wins; otherwise prefer the scraped
-      // value, smart-adjusted (minus one) during SUMMER when the year level has
-      // not yet advanced.
+      const settings = await browser.storage.local.get(['truncateDescription', 'showYearLevel']);
       header.showYearLevel = settings.showYearLevel !== false;
-      const custom = String(settings.customYearLevel || '').trim();
-      if (custom) {
-        header.yearLevel = custom;
-      } else if (/summer/i.test(selectedPeriod || '')) {
-        const n = parseInt(header.yearLevel, 10);
-        if (Number.isFinite(n) && n > 1) header.yearLevel = String(n - 1);
-      }
       const res = await browser.runtime.sendMessage({
         type: 'generate-pdf',
         data: { header, courses: included, totalUnits, truncateDescription: settings.truncateDescription !== false }
@@ -199,6 +249,38 @@
     }
   }
 
+  // Export another format (csv/json/xlsx/nextup). Reuses scrapeStudyLoad so
+  // every format gets the same header/courses/totalUnits payload and the same
+  // hybrid year-level resolution.
+  async function onExport(format) {
+    try {
+      const { header, courses, period, year } = await scrapeStudyLoad();
+      const included = ISMIStools.filterStudyLoadCourses(courses);
+      if (!included.length) throw new Error('No enrolled courses found.');
+      const totalUnits = ISMIStools.sumUnits(included);
+      const res = await browser.runtime.sendMessage({
+        type: 'export',
+        format,
+        data: { header, courses: included, totalUnits, period, year }
+      });
+      if (!res || !res.ok) throw new Error((res && res.error) || 'Export failed');
+      showToast('Exported ' + format.toUpperCase() + '.');
+    } catch (err) {
+      showToast('Error: ' + ((err && err.message) || err), true);
+    }
+  }
+
+  function makeExportButton(id, label, icon, format) {
+    const b = document.createElement('button');
+    b.id = id;
+    b.type = 'button';
+    b.className = 'btn green';
+    b.style.marginLeft = '6px';
+    b.innerHTML = '<i class="' + icon + '"></i> ' + label;
+    b.addEventListener('click', () => onExport(format));
+    return b;
+  }
+
   function injectDownloadButton() {
     if (document.getElementById(BTN_ID)) return;
     const unitsP = findTotalUnitsP();
@@ -209,6 +291,7 @@
     wrapper.style.alignItems = 'center';
     wrapper.style.justifyContent = 'space-between';
     wrapper.style.margin = '10px 0';
+    wrapper.style.flexWrap = 'wrap';
 
     const btn = document.createElement('button');
     btn.id = BTN_ID;
@@ -217,8 +300,21 @@
     btn.innerHTML = '<i class="fa fa-download"></i> Download PDF';
     btn.addEventListener('click', onDownloadPdf);
 
+    const btnCsv = makeExportButton('ismisHelperExportCsvBtn', 'CSV', 'fa fa-file-text-o', 'csv');
+    const btnXlsx = makeExportButton('ismisHelperExportXlsxBtn', 'Excel', 'fa fa-file-o', 'xlsx');
+    const btnJson = makeExportButton('ismisHelperExportJsonBtn', 'JSON', 'fa fa-file-code-o', 'json');
+    const btnNextUp = makeExportButton('ismisHelperExportNextUpBtn', 'Next Up', 'fa fa-calendar', 'nextup');
+
+    const btnGroup = document.createElement('div');
+    btnGroup.style.display = 'flex';
+    btnGroup.appendChild(btn);
+    btnGroup.appendChild(btnCsv);
+    btnGroup.appendChild(btnXlsx);
+    btnGroup.appendChild(btnJson);
+    btnGroup.appendChild(btnNextUp);
+
     unitsP.parentNode.insertBefore(wrapper, unitsP);
-    wrapper.appendChild(btn);
+    wrapper.appendChild(btnGroup);
     wrapper.appendChild(unitsP);
   }