fix: duplicate optAutoRedact ID + hardcoded log limit + add test suite

Bug 1: popup.html had duplicate id="optAutoRedact" on both the
Auto Redact toggle and Auto-redact Detected PII toggle. The second
overwrote the first, making the Auto Redact setting uncontrollable.
Fixed by giving the second toggle id="optAutoRedactDetected".

Bug 2: injector.js hardcoded activity log trim to 100, ignoring the
user's maxLogEntries setting. Now reads the setting from storage.

Added test-suite.html with 35+ tests covering storage, encryption,
sync (encryption-mandatory flows), auto-redact (built-in + custom
patterns), substitution engine, smart patterns, and auto-detect.

https://claude.ai/code/session_01KF4i7Ra7zCEDskxDBaNtcT

src/content/injector.js

@@ -91,6 +91,8 @@
         // Also log directly from the injector (content script world)
         // in case the background worker is asleep
         const replacements = event.data.replacements || [];
+        const settingsResult = await api.storage.local.get('ss_settings');
+        const maxLog = settingsResult.ss_settings?.maxLogEntries || 100;
         for (const r of replacements) {
           const log = (await api.storage.local.get('ss_activity_log')).ss_activity_log || [];
           log.unshift({
@@ -104,8 +106,8 @@
             pattern: r.pattern || '',
             url: location.href,
           });
-          // Trim
-          if (log.length > 100) log.length = 100;
+          // Trim to user-configured max
+          if (log.length > maxLog) log.length = maxLog;
           await api.storage.local.set({ ss_activity_log: log });
         }
       }

src/popup/popup.html

@@ -217,7 +217,7 @@
           <strong>Auto-redact detected PII</strong>
           <span class="setting-desc">Replace detected PII with placeholders on send</span>
         </div>
-        <label class="toggle"><input type="checkbox" id="optAutoRedact" checked><span class="toggle-slider"></span></label>
+        <label class="toggle"><input type="checkbox" id="optAutoRedactDetected" checked><span class="toggle-slider"></span></label>
       </div>
 
       <div class="setting-item">

src/popup/popup.js

@@ -222,7 +222,7 @@ async function initUnlockedUI() {
   // Load options tab settings
   $('#optAutoRedact').checked = settings.autoRedact !== false;
   $('#optAutoDetect').checked = settings.autoDetect !== false;
-  $('#optAutoRedact').checked = settings.autoRedactDetected !== false;
+  $('#optAutoRedactDetected').checked = settings.autoRedactDetected !== false;
   $('#optHighlights').checked = settings.showHighlights || false;
   $('#optDocPreview').checked = settings.docScanPreview !== false;
 
@@ -230,7 +230,7 @@ async function initUnlockedUI() {
   const optHandlers = [
     ['optAutoRedact', 'autoRedact'],
     ['optAutoDetect', 'autoDetect'],
-    ['optAutoRedact', 'autoRedactDetected'],
+    ['optAutoRedactDetected', 'autoRedactDetected'],
     ['optHighlights', 'showHighlights'],
     ['optDocPreview', 'docScanPreview'],
   ];