diff --git a/context/CONTEXT_2026-02-17_06-33-23.md b/context/CONTEXT_2026-02-17_06-33-23.md
new file mode 100644
index 00000000..aeae2029
--- /dev/null
+++ b/context/CONTEXT_2026-02-17_06-33-23.md
@@ -0,0 +1,4 @@
+# Context for Perf Agent Tue Feb 17 06:33:23 UTC 2026
+
+Goal: Daily performance improvement.
+Scope: Scan codebase for perf issues, fix one if safe, audit docs.
diff --git a/daily-perf-report-2026-02-17.md b/daily-perf-report-2026-02-17.md
new file mode 100644
index 00000000..1fd23d90
--- /dev/null
+++ b/daily-perf-report-2026-02-17.md
@@ -0,0 +1,30 @@
+# Daily Performance Report - 2026-02-17
+
+**Summary**: Identified and fixed background CPU usage in `ExploreDataService` when the tab is hidden. Found unbounded concurrency in `RelayHealthService`.
+
+## Findings
+
+### P1: Background Interval Leaks (Fixed)
+- **File**: `js/services/exploreDataService.js`
+- **Issue**: `startIntervals()` initiated recurring timers (watch history sync, tag IDF calc) even if `document.hidden` was true at startup (e.g., background tab load).
+- **Impact**: Wasted CPU and network in background tabs.
+- **Fix**: Added explicit `document.hidden` check in `startIntervals`.
+
+### P2: Unbounded Concurrency (Identified)
+- **File**: `js/services/relayHealthService.js`
+- **Issue**: `refresh()` uses `Promise.allSettled(urls.map(...))` to check all relays simultaneously.
+- **Impact**: Can spike network connections (N+1) if the relay list is large.
+- **Recommendation**: Implement a concurrency pool (e.g., limit to 3 parallel checks).
+
+### Linting Issues
+- `npm run lint:hex` failed with `ENOBUFS` due to large `js/webtorrent.min.js`.
+- **Fix**: Increased `spawnSync` buffer size in `scripts/check-hex.js` and added exclusion (though git grep exclusion logic seems flaky for this file).
+
+## Metrics
+- **Login Time**: Not measured this run.
+- **Background CPU**: Expected reduction in background tab CPU usage due to `ExploreDataService` fix.
+
+## Actions Taken
+- [x] Patched `js/services/exploreDataService.js`.
+- [x] Patched `scripts/check-hex.js` to fix linter crash.
+- [x] Created `perf/hits-2026-02-17.json` inventory.
diff --git a/docs/agents/task-logs/daily/2026-02-17_06-45-57_perf-agent_completed.md b/docs/agents/task-logs/daily/2026-02-17_06-45-57_perf-agent_completed.md
new file mode 100644
index 00000000..4211216c
--- /dev/null
+++ b/docs/agents/task-logs/daily/2026-02-17_06-45-57_perf-agent_completed.md
@@ -0,0 +1,6 @@
+# perf-agent completed
+
+- Fixed background CPU usage in `js/services/exploreDataService.js`.
+- Identified unbounded concurrency in `js/services/relayHealthService.js`.
+- Fixed `npm run lint:hex` crash due to large minified file (which was a transient artifact but exposed a buffer limit).
+- Generated `daily-perf-report-2026-02-17.md`.
diff --git a/js/services/exploreDataService.js b/js/services/exploreDataService.js
index 27efcd44..ca8998be 100644
--- a/js/services/exploreDataService.js
+++ b/js/services/exploreDataService.js
@@ -167,6 +167,11 @@ export default class ExploreDataService {
 
   startIntervals() {
     this.clearIntervals();
+
+    if (typeof document !== "undefined" && document.hidden) {
+      return;
+    }
+
     if (Number.isFinite(this.historyRefreshIntervalMs) && this.historyRefreshIntervalMs > 0) {
       this.watchHistoryInterval = setInterval(() => {
         this.refreshWatchHistoryTagCounts({ reason: "interval" });
diff --git a/perf/hits-2026-02-17.json b/perf/hits-2026-02-17.json
new file mode 100644
index 00000000..43c83db9
--- /dev/null
+++ b/perf/hits-2026-02-17.json
@@ -0,0 +1,26 @@
+[
+  {
+    "file": "js/services/exploreDataService.js",
+    "pattern": "setInterval",
+    "line": 171,
+    "trigger": "page load / initialization",
+    "impact": "Starts background intervals (watch history sync, tag IDF calc) even if tab is hidden.",
+    "fix": "Check document.hidden inside startIntervals()."
+  },
+  {
+    "file": "js/services/relayHealthService.js",
+    "pattern": "Promise.allSettled",
+    "line": 239,
+    "trigger": "refresh() called (e.g. periodically or on demand)",
+    "impact": "Unbounded concurrency for relay checks. If many relays, spawns many connections.",
+    "fix": "Use a concurrency limit (e.g. p-limit equivalent)."
+  },
+  {
+    "file": "js/ui/loginModalController.js",
+    "pattern": "setInterval",
+    "line": 395,
+    "trigger": "login modal open",
+    "impact": "Polls for modal close if MutationObserver fails. Checked document.hidden but context is complex.",
+    "fix": "Ensure visibility checks are robust."
+  }
+]
diff --git a/scripts/check-hex.js b/scripts/check-hex.js
index ee1a56b3..ad540e4b 100755
--- a/scripts/check-hex.js
+++ b/scripts/check-hex.js
@@ -35,7 +35,8 @@ const IGNORED_GLOBS = [
   'releases/**',
   'bitvid-working-webtorrent/**',
   'scripts/agent/**',
-  'docs/capacitor-native-app-plan.md'
+  'docs/capacitor-native-app-plan.md',
+  'js/webtorrent.min.js'
 ];
 
 const gitArgs = [
@@ -55,7 +56,9 @@ for (const glob of IGNORED_GLOBS) {
 
 // We rely on 'git' being available and 'git grep' supporting -P.
 // Typically available in most CI/dev environments.
-const result = spawnSync('git', gitArgs, { encoding: 'utf8' });
+// Increase maxBuffer to 10MB to avoid ENOBUFS on large outputs.
+console.log("Running git with args:", gitArgs.join(" "));
+const result = spawnSync('git', gitArgs, { encoding: 'utf8', maxBuffer: 1024 * 1024 * 10 });
 
 if (result.error) {
   console.error('Failed to execute git grep:', result.error.message);