ci: update go-server-coverage.json [skip ci]

## Why

The Azure staging VM (`meshcore-vm`) is offline. Self-hosted runners are
unavailable, blocking all CI.

## What changed (per job)

| Job | Change | Revert |
|-----|--------|--------|
| `e2e-test` | `runs-on: [self-hosted, Linux]` → `ubuntu-latest`;
removed self-hosted-specific "Free disk space" step | Change `runs-on`
back to `[self-hosted, Linux]`, restore disk cleanup step |
| `build-and-publish` | `runs-on: [self-hosted, meshcore-runner-2]` →
`ubuntu-latest`; removed "Free disk space" prune step (noop on fresh
GH-hosted runners) | Change `runs-on` back, restore prune step |
| `deploy` | `if: false # disabled` (was `github.event_name == 'push'`);
`runs-on` kept as-is | Change `if:` back to `github.event_name ==
'push'` |
| `publish` | `runs-on: [self-hosted, Linux]` → `ubuntu-latest`; `needs:
[deploy]` → `needs: [build-and-publish]` | Change both back |

## Notes

- `go-test` and `release-artifacts` were already on `ubuntu-latest` —
untouched.
- The `deploy` job is disabled via `if: false` for trivial one-line
revert when the VM returns.
- No new `setup-*` actions were needed — `setup-node`, `setup-go`,
`docker/setup-buildx-action`, and `docker/login-action` were already
present.

Co-authored-by: you <you@example.com>

.badges/e2e-tests.json

@@ -1 +1 @@
-{"schemaVersion":1,"label":"e2e tests","message":"45 passed","color":"brightgreen"}
+{"schemaVersion":1,"label":"e2e tests","message":"82 passed","color":"brightgreen"}

.badges/frontend-coverage.json

@@ -1 +1 @@
-{"schemaVersion":1,"label":"frontend coverage","message":"39.68%","color":"red"}
+{"schemaVersion":1,"label":"frontend coverage","message":"37.26%","color":"red"}

.github/workflows/deploy.yml

@@ -135,7 +135,7 @@ jobs:
   e2e-test:
     name: "🎭 Playwright E2E Tests"
     needs: [go-test]
-    runs-on: [self-hosted, Linux]
+    runs-on: ubuntu-latest
     defaults:
       run:
         shell: bash
@@ -145,13 +145,6 @@ jobs:
         with:
           fetch-depth: 0
 
-      - name: Free disk space
-        run: |
-          # Prune old runner diagnostic logs (can accumulate 50MB+)
-          find ~/actions-runner/_diag/ -name '*.log' -mtime +3 -delete 2>/dev/null || true
-          # Show available disk space
-          df -h / | tail -1
-
       - name: Set up Node.js 22
         uses: actions/setup-node@v5
         with:
@@ -252,17 +245,11 @@ jobs:
   build-and-publish:
     name: "🏗️ Build & Publish Docker Image"
     needs: [e2e-test]
-    runs-on: [self-hosted, meshcore-runner-2]
+    runs-on: ubuntu-latest
     steps:
       - name: Checkout code
         uses: actions/checkout@v5
 
-      - name: Free disk space
-        run: |
-          docker system prune -af 2>/dev/null || true
-          docker builder prune -af 2>/dev/null || true
-          df -h /
-
       - name: Compute build metadata
         id: meta
         run: |
@@ -372,7 +359,7 @@ jobs:
   # ───────────────────────────────────────────────────────────────
   deploy:
     name: "🚀 Deploy Staging"
-    if: github.event_name == 'push'
+    if: false  # disabled: staging VM offline, manual deploy required
     needs: [build-and-publish]
     runs-on: [self-hosted, meshcore-runner-2]
     steps:
@@ -461,8 +448,8 @@ jobs:
   publish:
     name: "📝 Publish Badges & Summary"
     if: github.event_name == 'push'
-    needs: [deploy]
-    runs-on: [self-hosted, Linux]
+    needs: [build-and-publish]
+    runs-on: ubuntu-latest
     steps:
       - name: Checkout code
         uses: actions/checkout@v5

cmd/server/clock_skew.go

@@ -120,8 +120,6 @@ type NodeClockSkew struct {
 	GoodFraction        float64  `json:"goodFraction"`        // fraction of recent samples with |skew| <= 1h
 	RecentBadSampleCount int     `json:"recentBadSampleCount"` // count of recent samples with |skew| > 1h
 	RecentSampleCount    int     `json:"recentSampleCount"`    // total recent samples in window
-	RecentHashEvidence  []HashEvidence      `json:"recentHashEvidence,omitempty"`
-	CalibrationSummary  *CalibrationSummary `json:"calibrationSummary,omitempty"`
 	NodeName        string       `json:"nodeName,omitempty"` // populated in fleet responses
 	NodeRole        string       `json:"nodeRole,omitempty"` // populated in fleet responses
 }
@@ -132,31 +130,6 @@ type SkewSample struct {
 	SkewSec   float64 `json:"skew"` // corrected skew in seconds
 }
 
-// HashEvidenceObserver is one observer's contribution to a per-hash evidence entry.
-type HashEvidenceObserver struct {
-	ObserverID      string  `json:"observerID"`
-	ObserverName    string  `json:"observerName"`
-	RawSkewSec      float64 `json:"rawSkewSec"`
-	CorrectedSkewSec float64 `json:"correctedSkewSec"`
-	ObserverOffsetSec float64 `json:"observerOffsetSec"`
-	Calibrated      bool    `json:"calibrated"`
-}
-
-// HashEvidence is per-hash clock skew evidence showing individual observer contributions.
-type HashEvidence struct {
-	Hash                  string                 `json:"hash"`
-	Observers             []HashEvidenceObserver `json:"observers"`
-	MedianCorrectedSkewSec float64              `json:"medianCorrectedSkewSec"`
-	Timestamp             int64                  `json:"timestamp"`
-}
-
-// CalibrationSummary counts how many samples were corrected via observer calibration.
-type CalibrationSummary struct {
-	TotalSamples       int `json:"totalSamples"`
-	CalibratedSamples  int `json:"calibratedSamples"`
-	UncalibratedSamples int `json:"uncalibratedSamples"`
-}
-
 // txSkewResult maps tx hash → per-transmission skew stats. This is an
 // intermediate result keyed by hash (not pubkey); the store maps hash → pubkey
 // when building the final per-node view.
@@ -170,27 +143,15 @@ type ClockSkewEngine struct {
 	observerOffsets  map[string]float64 // observerID → calibrated offset (seconds)
 	observerSamples  map[string]int     // observerID → number of multi-observer packets used
 	nodeSkew         txSkewResult
-	hashEvidence     map[string][]hashEvidenceEntry // hash → per-observer raw/corrected data
 	lastComputed     time.Time
 	computeInterval  time.Duration
 }
 
-// hashEvidenceEntry stores raw evidence per observer per hash, cached during Recompute.
-type hashEvidenceEntry struct {
-	observerID  string
-	rawSkew     float64
-	corrected   float64
-	offset      float64
-	calibrated  bool
-	observedTS  int64
-}
-
 func NewClockSkewEngine() *ClockSkewEngine {
 	return &ClockSkewEngine{
 		observerOffsets:  make(map[string]float64),
 		observerSamples: make(map[string]int),
 		nodeSkew:       make(txSkewResult),
-		hashEvidence:   make(map[string][]hashEvidenceEntry),
 		computeInterval: 30 * time.Second,
 	}
 }
@@ -215,16 +176,14 @@ func (e *ClockSkewEngine) Recompute(store *PacketStore) {
 	var newOffsets map[string]float64
 	var newSamples map[string]int
 	var newNodeSkew txSkewResult
-	var newHashEvidence map[string][]hashEvidenceEntry
 
 	if len(samples) > 0 {
 		newOffsets, newSamples = calibrateObservers(samples)
-		newNodeSkew, newHashEvidence = computeNodeSkew(samples, newOffsets)
+		newNodeSkew = computeNodeSkew(samples, newOffsets)
 	} else {
 		newOffsets = make(map[string]float64)
 		newSamples = make(map[string]int)
 		newNodeSkew = make(txSkewResult)
-		newHashEvidence = make(map[string][]hashEvidenceEntry)
 	}
 
 	// Swap results under brief write lock.
@@ -237,7 +196,6 @@ func (e *ClockSkewEngine) Recompute(store *PacketStore) {
 	e.observerOffsets = newOffsets
 	e.observerSamples = newSamples
 	e.nodeSkew = newNodeSkew
-	e.hashEvidence = newHashEvidence
 	e.lastComputed = time.Now()
 	e.mu.Unlock()
 }
@@ -374,7 +332,7 @@ func calibrateObservers(samples []skewSample) (map[string]float64, map[string]in
 // ── Phase 3: Per-Node Skew ─────────────────────────────────────────────────────
 
 // computeNodeSkew calculates corrected skew statistics for each node.
-func computeNodeSkew(samples []skewSample, obsOffsets map[string]float64) (txSkewResult, map[string][]hashEvidenceEntry) {
+func computeNodeSkew(samples []skewSample, obsOffsets map[string]float64) txSkewResult {
 	// Compute corrected skew per sample, grouped by hash (each hash = one
 	// node's advert transmission). The caller maps hash → pubkey via byNode.
 	type correctedSample struct {
@@ -385,7 +343,6 @@ func computeNodeSkew(samples []skewSample, obsOffsets map[string]float64) (txSke
 
 	byHash := make(map[string][]correctedSample)
 	hashAdvertTS := make(map[string]int64)
-	evidence := make(map[string][]hashEvidenceEntry) // hash → per-observer evidence
 
 	for _, s := range samples {
 		obsOffset, hasCal := obsOffsets[s.observerID]
@@ -402,14 +359,6 @@ func computeNodeSkew(samples []skewSample, obsOffsets map[string]float64) (txSke
 			calibrated: hasCal,
 		})
 		hashAdvertTS[s.hash] = s.advertTS
-		evidence[s.hash] = append(evidence[s.hash], hashEvidenceEntry{
-			observerID: s.observerID,
-			rawSkew:    round(rawSkew, 1),
-			corrected:  round(corrected, 1),
-			offset:     round(obsOffset, 1),
-			calibrated: hasCal,
-			observedTS: s.observedTS,
-		})
 	}
 
 	// Each hash represents one advert from one node. Compute median corrected
@@ -448,7 +397,7 @@ func computeNodeSkew(samples []skewSample, obsOffsets map[string]float64) (txSke
 			LastObservedTS: latestObsTS,
 		}
 	}
-	return result, evidence
+	return result
 }
 
 // ── Integration with PacketStore ───────────────────────────────────────────────
@@ -609,70 +558,6 @@ func (s *PacketStore) getNodeClockSkewLocked(pubkey string) *NodeClockSkew {
 		samples[i] = SkewSample{Timestamp: p.ts, SkewSec: round(p.skew, 1)}
 	}
 
-	// Build per-hash evidence (most recent 10 hashes with ≥1 observer).
-	// Observer name lookup from store observations.
-	obsNameMap := make(map[string]string)
-	type hashMeta struct {
-		hash string
-		ts   int64
-	}
-	var evidenceHashes []hashMeta
-	for _, tx := range txs {
-		if tx.PayloadType == nil || *tx.PayloadType != PayloadADVERT {
-			continue
-		}
-		ev, ok := s.clockSkew.hashEvidence[tx.Hash]
-		if !ok || len(ev) == 0 {
-			continue
-		}
-		// Collect observer names from tx observations.
-		for _, obs := range tx.Observations {
-			if obs.ObserverID != "" && obs.ObserverName != "" {
-				obsNameMap[obs.ObserverID] = obs.ObserverName
-			}
-		}
-		evidenceHashes = append(evidenceHashes, hashMeta{hash: tx.Hash, ts: ev[0].observedTS})
-	}
-	// Sort by timestamp descending, take most recent 10.
-	sort.Slice(evidenceHashes, func(i, j int) bool { return evidenceHashes[i].ts > evidenceHashes[j].ts })
-	if len(evidenceHashes) > 10 {
-		evidenceHashes = evidenceHashes[:10]
-	}
-	var recentEvidence []HashEvidence
-	var calSummary CalibrationSummary
-	for _, eh := range evidenceHashes {
-		entries := s.clockSkew.hashEvidence[eh.hash]
-		var observers []HashEvidenceObserver
-		var corrSkews []float64
-		for _, e := range entries {
-			name := obsNameMap[e.observerID]
-			if name == "" {
-				name = e.observerID
-			}
-			observers = append(observers, HashEvidenceObserver{
-				ObserverID:       e.observerID,
-				ObserverName:     name,
-				RawSkewSec:       e.rawSkew,
-				CorrectedSkewSec: e.corrected,
-				ObserverOffsetSec: e.offset,
-				Calibrated:       e.calibrated,
-			})
-			corrSkews = append(corrSkews, e.corrected)
-			calSummary.TotalSamples++
-			if e.calibrated {
-				calSummary.CalibratedSamples++
-			} else {
-				calSummary.UncalibratedSamples++
-			}
-		}
-		recentEvidence = append(recentEvidence, HashEvidence{
-			Hash:                   eh.hash,
-			Observers:              observers,
-			MedianCorrectedSkewSec: round(median(corrSkews), 1),
-			Timestamp:              eh.ts,
-		})
-	}
-
 	return &NodeClockSkew{
 		Pubkey:               pubkey,
 		MeanSkewSec:          round(meanSkew, 1),
@@ -689,8 +574,6 @@ func (s *PacketStore) getNodeClockSkewLocked(pubkey string) *NodeClockSkew {
 		GoodFraction:         round(goodFraction, 2),
 		RecentBadSampleCount: recentBadCount,
 		RecentSampleCount:    recentSampleCount,
-		RecentHashEvidence:   recentEvidence,
-		CalibrationSummary:   &calSummary,
 	}
 }
 
@@ -718,10 +601,8 @@ func (s *PacketStore) GetFleetClockSkew() []*NodeClockSkew {
 			cs.NodeName = ni.Name
 			cs.NodeRole = ni.Role
 		}
-		// Omit samples and evidence in fleet response (too much data).
+		// Omit samples in fleet response (too much data).
 		cs.Samples = nil
-		cs.RecentHashEvidence = nil
-		cs.CalibrationSummary = nil
 		results = append(results, cs)
 	}
 	return results

cmd/server/clock_skew_test.go

@@ -191,7 +191,7 @@ func TestComputeNodeSkew_BasicCorrection(t *testing.T) {
 	// So the median approach finds obs2 is +5 ahead (relative to median)
 
 	// Now compute node skew with those offsets:
-	nodeSkew, _ := computeNodeSkew(samples, offsets)
+	nodeSkew := computeNodeSkew(samples, offsets)
 	cs, ok := nodeSkew["h1"]
 	if !ok {
 		t.Fatal("expected skew data for hash h1")
@@ -220,7 +220,7 @@ func TestComputeNodeSkew_ThreeObservers(t *testing.T) {
 		t.Errorf("obs3 offset = %v, want 30", offsets["obs3"])
 	}
 
-	nodeSkew, _ := computeNodeSkew(samples, offsets)
+	nodeSkew := computeNodeSkew(samples, offsets)
 	cs := nodeSkew["h1"]
 	if cs == nil {
 		t.Fatal("expected skew data for h1")
@@ -954,104 +954,3 @@ func TestAllGood_OK_845(t *testing.T) {
 		t.Errorf("recentBadSampleCount = %v, want 0", r.RecentBadSampleCount)
 	}
 }
-
-func TestNodeClockSkew_EvidencePayload(t *testing.T) {
-	// 3-observer scenario: obs1 ahead by +2s, obs2 on time, obs3 behind by -1s.
-	// Node clock is 60s ahead. Raw skew = advertTS - obsTS.
-	// Hash has 3 observations, each observer sees same advert.
-	ps := NewPacketStore(nil, nil)
-
-	pt := 4 // ADVERT
-	// Advert timestamp: 1700000060 (node 60s ahead of true time 1700000000)
-	// obs1 sees at 1700000002 (2s ahead of true time)  → raw = 60 - 2 = 58
-	// obs2 sees at 1700000000 (on time)                 → raw = 60 - 0 = 60
-	// obs3 sees at 1699999999 (-1s, behind)             → raw = 60 + 1 = 61
-	// Median obsTS = 1700000000, so:
-	//   obs1 offset = 1700000002 - 1700000000 = +2
-	//   obs2 offset = 0
-	//   obs3 offset = 1699999999 - 1700000000 = -1
-	// Corrected: raw + offset → obs1: 58+2=60, obs2: 60+0=60, obs3: 61+(-1)=60
-
-	tx1 := &StoreTx{
-		Hash:        "evidence_hash_1",
-		PayloadType: &pt,
-		DecodedJSON: `{"payload":{"timestamp":1700000060}}`,
-		Observations: []*StoreObs{
-			{ObserverID: "obs1", ObserverName: "Observer Alpha", Timestamp: "2023-11-14T22:13:22Z"},
-			{ObserverID: "obs2", ObserverName: "Observer Beta", Timestamp: "2023-11-14T22:13:20Z"},
-			{ObserverID: "obs3", ObserverName: "Observer Gamma", Timestamp: "2023-11-14T22:13:19Z"},
-		},
-	}
-	// Second hash to ensure we get multiple evidence entries.
-	tx2 := &StoreTx{
-		Hash:        "evidence_hash_2",
-		PayloadType: &pt,
-		DecodedJSON: `{"payload":{"timestamp":1700003660}}`,
-		Observations: []*StoreObs{
-			{ObserverID: "obs1", ObserverName: "Observer Alpha", Timestamp: "2023-11-14T23:13:22Z"},
-			{ObserverID: "obs2", ObserverName: "Observer Beta", Timestamp: "2023-11-14T23:13:20Z"},
-			{ObserverID: "obs3", ObserverName: "Observer Gamma", Timestamp: "2023-11-14T23:13:19Z"},
-		},
-	}
-
-	ps.mu.Lock()
-	ps.byNode["NODETEST"] = []*StoreTx{tx1, tx2}
-	ps.byPayloadType[4] = []*StoreTx{tx1, tx2}
-	ps.clockSkew.computeInterval = 0
-	ps.mu.Unlock()
-
-	r := ps.GetNodeClockSkew("NODETEST")
-	if r == nil {
-		t.Fatal("expected clock skew result")
-	}
-
-	// Check recentHashEvidence exists.
-	if len(r.RecentHashEvidence) == 0 {
-		t.Fatal("expected recentHashEvidence to be populated")
-	}
-	if len(r.RecentHashEvidence) != 2 {
-		t.Errorf("recentHashEvidence length = %d, want 2", len(r.RecentHashEvidence))
-	}
-
-	// Check first evidence entry has 3 observers.
-	ev := r.RecentHashEvidence[0]
-	if len(ev.Observers) != 3 {
-		t.Fatalf("evidence observers = %d, want 3", len(ev.Observers))
-	}
-
-	// Verify corrected = raw + offset for each observer.
-	for _, o := range ev.Observers {
-		expected := o.RawSkewSec + o.ObserverOffsetSec
-		if math.Abs(o.CorrectedSkewSec-expected) > 0.2 {
-			t.Errorf("observer %s: corrected=%.1f, expected raw(%.1f)+offset(%.1f)=%.1f",
-				o.ObserverID, o.CorrectedSkewSec, o.RawSkewSec, o.ObserverOffsetSec, expected)
-		}
-	}
-
-	// All corrected values should be ~60s (node is 60s ahead).
-	if math.Abs(ev.MedianCorrectedSkewSec-60) > 1 {
-		t.Errorf("median corrected = %.1f, want ~60", ev.MedianCorrectedSkewSec)
-	}
-
-	// Check calibration summary.
-	if r.CalibrationSummary == nil {
-		t.Fatal("expected calibrationSummary")
-	}
-	if r.CalibrationSummary.TotalSamples != 6 { // 3 observers × 2 hashes
-		t.Errorf("calibration total = %d, want 6", r.CalibrationSummary.TotalSamples)
-	}
-	if r.CalibrationSummary.CalibratedSamples != 6 {
-		t.Errorf("calibrated = %d, want 6 (all multi-observer)", r.CalibrationSummary.CalibratedSamples)
-	}
-
-	// Check observer names are populated.
-	nameFound := false
-	for _, o := range ev.Observers {
-		if o.ObserverName == "Observer Alpha" || o.ObserverName == "Observer Beta" {
-			nameFound = true
-		}
-	}
-	if !nameFound {
-		t.Error("expected observer names to be populated from tx observations")
-	}
-}

public/nodes.js

@@ -815,41 +815,6 @@
    * Shared between the full-screen detail page and the side panel (#813, #690).
    * No-op if the container is missing, the API errors, or the response lacks severity.
    */
-  /** Build collapsible evidence panel for node clock skew card */
-  function buildEvidencePanel(cs) {
-    var evidence = cs.recentHashEvidence;
-    if (!evidence || evidence.length === 0) return '';
-
-    var calSum = cs.calibrationSummary || {};
-    var calLine = calSum.totalSamples
-      ? '<div style="font-size:11px;color:var(--text-muted);margin-bottom:6px">Last ' + calSum.totalSamples + ' samples: ' + (calSum.calibratedSamples || 0) + ' corrected via observer calibration, ' + (calSum.uncalibratedSamples || 0) + ' uncorrected (single-observer).</div>'
-      : '';
-
-    // Severity reason.
-    var skewVal = window.currentSkewValue(cs);
-    var sampleCount = (cs.samples || []).length;
-    var sevLabel = SKEW_SEVERITY_LABELS[cs.severity] || cs.severity;
-    var reasonLine = '<div style="font-size:12px;margin-bottom:8px"><strong>Recent ' + sampleCount + ' adverts median ' + formatSkew(skewVal) + ' → ' + sevLabel + '</strong></div>';
-
-    var hashBlocks = evidence.map(function(ev) {
-      var shortHash = (ev.hash || '').substring(0, 8) + '…';
-      var obsCount = ev.observers ? ev.observers.length : 0;
-      var header = '<div style="font-weight:600;font-size:12px;margin-top:6px">Hash ' + shortHash + '  ·  ' + obsCount + ' observer' + (obsCount !== 1 ? 's' : '') + '  ·  median corrected: ' + formatSkew(ev.medianCorrectedSkewSec) + '</div>';
-      var lines = (ev.observers || []).map(function(o) {
-        var name = o.observerName || o.observerID;
-        return '<div style="font-size:11px;padding-left:16px;font-family:var(--mono)">' +
-          name + '   raw=' + formatSkew(o.rawSkewSec) + '  corrected=' + formatSkew(o.correctedSkewSec) + '  (observer offset ' + formatSkew(o.observerOffsetSec) + ')' +
-          '</div>';
-      }).join('');
-      return header + lines;
-    }).join('');
-
-    return '<details style="margin-top:10px"><summary style="cursor:pointer;font-size:12px;color:var(--text-muted)">Evidence (' + evidence.length + ' hashes)</summary>' +
-      '<div style="margin-top:6px;padding:8px;background:var(--bg-secondary);border-radius:6px">' +
-      reasonLine + calLine + hashBlocks +
-      '</div></details>';
-  }
-
   async function loadClockSkewInto(container, pubkey) {
     if (!container) return;
     try {
@@ -876,8 +841,7 @@
         '</div>' +
         driftHtml +
         (sparkHtml ? '<div class="skew-sparkline-wrap" style="margin-top:8px">' + sparkHtml + '<div style="font-size:10px;color:var(--text-muted)">Skew over time (' + (cs.samples || []).length + ' samples)</div></div>' : '') +
-        bimodalWarning +
-        buildEvidencePanel(cs);
+        bimodalWarning;
     } catch (e) {
       // Non-fatal — section stays hidden
     }

public/observer-detail.js

@@ -70,24 +70,18 @@
     try {
       destroyCharts();
       chartDefaults();
-      const [obs, analytics, obsSkewArr] = await Promise.all([
+      const [obs, analytics] = await Promise.all([
         api('/observers/' + encodeURIComponent(currentId)),
         api('/observers/' + encodeURIComponent(currentId) + '/analytics?days=' + currentDays),
-        api('/observers/clock-skew', { ttl: 30000 }).catch(function() { return []; }),
       ]);
-      // Find this observer's calibration data.
-      var obsSkew = null;
-      (Array.isArray(obsSkewArr) ? obsSkewArr : []).forEach(function(s) {
-        if (s && s.observerID === currentId) obsSkew = s;
-      });
-      renderDetail(obs, analytics, obsSkew);
+      renderDetail(obs, analytics);
     } catch (e) {
       document.getElementById('obsDetailContent').innerHTML =
         '<div class="text-muted" style="padding:40px">Error: ' + e.message + '</div>';
     }
   }
 
-  function renderDetail(obs, analytics, obsSkew) {
+  function renderDetail(obs, analytics) {
     const el = document.getElementById('obsDetailContent');
     if (!el) return;
 
@@ -160,18 +154,6 @@
       <div class="mono" style="font-size:0.75em;color:var(--text-muted);margin-bottom:20px;word-break:break-all">
         ID: ${obs.id}
       </div>
-      ${obsSkew && obsSkew.samples > 0 ? `
-      <div class="node-full-card skew-detail-section" style="margin-bottom:20px;padding:12px">
-        <h4 style="margin:0 0 6px">⏰ Clock Offset</h4>
-        <div style="display:flex;align-items:center;gap:12px;flex-wrap:wrap">
-          <span style="font-size:18px;font-weight:700;font-family:var(--mono)">${formatSkew(obsSkew.offsetSec)}</span>
-          ${renderSkewBadge((function(abs) { return abs >= 300 ? (abs >= 3600 ? 'critical' : 'warning') : 'ok'; })(Math.abs(obsSkew.offsetSec)), obsSkew.offsetSec)}
-          <span class="text-muted" style="font-size:12px">${obsSkew.samples} sample${obsSkew.samples !== 1 ? 's' : ''}</span>
-        </div>
-        <div style="font-size:12px;color:var(--text-muted);margin-top:8px;max-width:600px">
-          <strong>How this is computed:</strong> when this observer and another observer see the same packet, we compare their receive timestamps. The median deviation across all multi-observer packets is this observer's offset.
-        </div>
-      </div>` : ''}
       <div class="obs-charts" style="display:grid;grid-template-columns:repeat(auto-fit,minmax(400px,1fr));gap:16px">
         <div class="chart-card" style="padding:12px">
           <h3 style="margin:0 0 8px;font-size:0.95em">Packets Over Time</h3>

public/observers.js

@@ -3,7 +3,6 @@
 
 (function () {
   let observers = [];
-  let obsSkewMap = {}; // observerID → {offsetSec, samples}
   let wsHandler = null;
   let refreshTimer = null;
   let regionChangeHandler = null;
@@ -52,20 +51,12 @@
     if (regionChangeHandler) RegionFilter.offChange(regionChangeHandler);
     regionChangeHandler = null;
     observers = [];
-    obsSkewMap = {};
   }
 
   async function loadObservers() {
     try {
-      const [data, skewData] = await Promise.all([
-        api('/observers', { ttl: CLIENT_TTL.observers }),
-        api('/observers/clock-skew', { ttl: 30000 }).catch(function() { return []; })
-      ]);
+      const data = await api('/observers', { ttl: CLIENT_TTL.observers });
       observers = data.observers || [];
-      obsSkewMap = {};
-      (Array.isArray(skewData) ? skewData : []).forEach(function(s) {
-        if (s && s.observerID) obsSkewMap[s.observerID] = s;
-      });
       render();
     } catch (e) {
       document.getElementById('obsContent').innerHTML =
@@ -133,7 +124,7 @@
         <caption class="sr-only">Observer status and statistics</caption>
         <thead><tr>
           <th scope="col">Status</th><th scope="col">Name</th><th scope="col">Region</th><th scope="col">Last Seen</th>
-          <th scope="col">Packets</th><th scope="col">Packets/Hour</th><th scope="col">Clock Offset</th><th scope="col">Uptime</th>
+          <th scope="col">Packets</th><th scope="col">Packets/Hour</th><th scope="col">Uptime</th>
         </tr></thead>
         <tbody>${filtered.map(o => {
           const h = healthStatus(o.last_seen);
@@ -145,12 +136,6 @@
             <td>${timeAgo(o.last_seen)}</td>
             <td>${(o.packet_count || 0).toLocaleString()}</td>
             <td>${sparkBar(o.packetsLastHour || 0, maxPktsHr)}</td>
-            <td>${(function() {
-              var sk = obsSkewMap[o.id];
-              if (!sk || sk.samples == null || sk.samples === 0) return '<span class="text-muted">—</span>';
-              var sev = (function(abs) { return abs >= 300 ? (abs >= 3600 ? 'critical' : 'warning') : 'ok'; })(Math.abs(sk.offsetSec));
-              return renderSkewBadge(sev, sk.offsetSec) + ' <span class="text-muted" title="Computed from ' + sk.samples + ' multi-observer packets. Positive = observer ahead of consensus.">(' + sk.samples + ')</span>';
-            })()}</td>
             <td>${uptimeStr(o.first_seen)}</td>
           </tr>`;
         }).join('')}</tbody>