fix: honor Output Root for single-LOG export + writable default output dir

src/main/logwriter.js

@@ -139,9 +139,8 @@ async function exportLog(payload = {}) {
 
 /**
  * Export ONLY one LOG (the active tab) as a single .log file carrying the
- * experiment-field header on top. Always lands in the in-project LOG_OUTPUT
- * folder (ignores any custom output root) so a half-finished experiment can be
- * shared for confirmation before the full export.
+ * experiment-field header on top. Honors the custom Output Root when one is
+ * set, otherwise falls back to the default LOG_OUTPUT folder.
  * Returns { ok, single, targetDir, filePath, fileName, files } or { ok:false, error }.
  */
 async function exportSingleLog(payload = {}) {
@@ -151,6 +150,7 @@ async function exportSingleLog(payload = {}) {
     tester = '',
     testCase = '',
     notes = '',
+    outputBase = '',
     customFields = [],
     log = {},
     abbrevLen,
@@ -174,9 +174,9 @@ async function exportSingleLog(payload = {}) {
         .filter((f) => f.label || f.value)
     : [];
 
-  // Single-LOG output: a dedicated folder under the in-project LOG_OUTPUT,
-  // with the one .log file (carrying the experiment header) inside it.
-  const baseDir = defaultOutputDir();
+  // Single-LOG output: a dedicated folder under the chosen Output Root (or the
+  // default LOG_OUTPUT when none is set), with the one .log file inside.
+  const baseDir = outputBase && outputBase.trim() ? outputBase.trim() : defaultOutputDir();
   const now = new Date();
   const nameMax = Math.min(40, Math.max(1, parseInt(abbrevLen, 10) || 30));
   const folderName = `${dateStamp(now)}_${timeStamp4(now)}_${abbreviate(experimentName, nameMax)}_${typeName}`;

src/main/paths.js

@@ -8,23 +8,51 @@
  */
 'use strict';
 
+const fs = require('fs');
 const path = require('path');
 const { app } = require('electron');
 
 /**
- * Base directory used as the writable root for output.
- * - Packaged: the folder that contains the installed M2_LOG.exe
- *   (per-user install under %LOCALAPPDATA%\Programs\M2_LOG is writable).
+ * Base directory used as the read root for bundled resources (e.g. highlight
+ * rules) and as the preferred output root.
+ * - Packaged: the folder that contains the installed M2_LOG.exe.
  * - Dev: the project root.
  */
 function appBaseDir() {
   if (app.isPackaged) return path.dirname(process.execPath);
   return path.join(__dirname, '..', '..');
 }
 
-/** Default output root: <appBaseDir>\LOG_OUTPUT */
+/** True if `dir` can be created and written to (Windows ACLs need a real probe). */
+function canWrite(dir) {
+  try {
+    fs.mkdirSync(dir, { recursive: true });
+    const probe = path.join(dir, `.m2log-write-test-${process.pid}-${Date.now()}.tmp`);
+    fs.writeFileSync(probe, '');
+    fs.unlinkSync(probe);
+    return true;
+  } catch (e) {
+    return false;
+  }
+}
+
+let cachedOutputDir = null;
+
+/**
+ * Default output root for exports and the LOG Analysis view.
+ * Prefers <appBaseDir>\LOG_OUTPUT (portable / per-user install). When the app
+ * is installed to a protected location (e.g. C:\Program Files) that folder is
+ * not writable, so we fall back to <Documents>\M2_LOG\LOG_OUTPUT.
+ */
 function defaultOutputDir() {
-  return path.join(appBaseDir(), 'LOG_OUTPUT');
+  if (cachedOutputDir) return cachedOutputDir;
+  const primary = path.join(appBaseDir(), 'LOG_OUTPUT');
+  if (!app.isPackaged || canWrite(primary)) {
+    cachedOutputDir = primary;
+  } else {
+    cachedOutputDir = path.join(app.getPath('documents'), 'M2_LOG', 'LOG_OUTPUT');
+  }
+  return cachedOutputDir;
 }
 
 module.exports = { appBaseDir, defaultOutputDir };

src/renderer/i18n/en.json

@@ -35,7 +35,7 @@
   "btn.clear": "Clear",
   "btn.clear.title": "Clear current LOG",
   "btn.exportSingle": "Export this LOG",
-  "btn.exportSingle.title": "Export only the current LOG (with the experiment header) to the in-project LOG_OUTPUT",
+  "btn.exportSingle.title": "Export only the current LOG (with the experiment header) to the Output Root (or LOG_OUTPUT if empty)",
   "toast.exportSingleOk": "This LOG exported (with header) to LOG_OUTPUT",
   "log.type.ph": "LOG type, e.g. UEFI",
   "log.content.ph": "Paste LOG here...",

src/renderer/i18n/zh.json

@@ -35,7 +35,7 @@
   "btn.clear": "清除",
   "btn.clear.title": "清空目前 LOG",
   "btn.exportSingle": "輸出此 LOG",
-  "btn.exportSingle.title": "只輸出目前這個 LOG（含實驗欄位表頭）到專案 LOG_OUTPUT",
+  "btn.exportSingle.title": "只輸出目前這個 LOG（含實驗欄位表頭）到輸出根目錄（留空則為 LOG_OUTPUT）",
   "toast.exportSingleOk": "已輸出此 LOG（含實驗表頭）到 LOG_OUTPUT",
   "log.type.ph": "LOG 種類，例如 UEFI",
   "log.content.ph": "在此貼上 LOG...",

src/renderer/index.html

@@ -175,7 +175,7 @@ <h2 data-i18n="panel.expFields">實驗欄位</h2>
             <div class="tabs" id="logTabs"></div>
             <div class="log-tools">
               <span class="counter" id="counter">0 行 · 0 字元</span>
-              <button class="btn btn-ghost btn-sm" id="btnExportSingle" data-i18n-title="btn.exportSingle.title" title="只輸出目前這個 LOG（含實驗欄位表頭）到專案 LOG_OUTPUT">
+              <button class="btn btn-ghost btn-sm" id="btnExportSingle" data-i18n-title="btn.exportSingle.title" title="只輸出目前這個 LOG（含實驗欄位表頭）到輸出根目錄（留空則為 LOG_OUTPUT）">
                 <svg viewBox="0 0 24 24" width="14" height="14" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
                   <path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4" />
                   <polyline points="7 10 12 15 17 10" />