From eb1f7427c4644072f66c930bf2b0da1fb62f335d Mon Sep 17 00:00:00 2001
From: Justin Visser <justinfvisser@gmail.com>
Date: Wed, 10 Jun 2026 17:51:21 +0200
Subject: [PATCH] web: panel management, slice 7 of M3

The kebab menu goes live: Edit and Rename open the PanelEditorPopover
(rename focuses the label in its header), Duplicate copies with a
' copy' suffix and the next accent, Remove deletes immediately and is
disabled on the last panel. Add scenario opens the new panel's editor
right away, still capped at six.

The editor offers the strategy select plus every Config field as a row
against the base value: a differing value becomes an override
(highlighted row, per-field reset, chips on the card), typing the base
value back clears it, and runs touch only that panel through the
debounce. Engine 400s appear inline in the popover with the offending
field marked.

Per-panel failures now leave a rose dot on the kebab while the panel
keeps its last good result; the store tracks failed panel ids and
clears them on the next successful run. Field and strategy labels moved
to lib/fieldLabels so controls, editor, and table share one vocabulary.
---
 web/src/components/AdvancedFields.vue         |  15 +-
 web/src/components/PanelEditorPopover.vue     | 297 ++++++++++++++++++
 web/src/components/PanelMenu.vue              | 107 +++++++
 web/src/components/ResultsTable.vue           |   9 +-
 web/src/components/ScenarioPanel.vue          |  94 +++++-
 web/src/components/ScenarioToolbar.vue        |   8 +-
 .../composables/__tests__/useSimStore.spec.ts |   3 +
 web/src/composables/useSimStore.ts            |  11 +
 web/src/lib/fieldLabels.ts                    |  21 ++
 9 files changed, 545 insertions(+), 20 deletions(-)
 create mode 100644 web/src/components/PanelEditorPopover.vue
 create mode 100644 web/src/components/PanelMenu.vue
 create mode 100644 web/src/lib/fieldLabels.ts

diff --git a/web/src/components/AdvancedFields.vue b/web/src/components/AdvancedFields.vue
index 9591f3b..4811496 100644
--- a/web/src/components/AdvancedFields.vue
+++ b/web/src/components/AdvancedFields.vue
@@ -1,6 +1,7 @@
 <script setup lang="ts">
 import { computed } from 'vue'
 import { useSimStore } from '@/composables/useSimStore'
+import { CONFIG_FIELD_LABELS } from '@/lib/fieldLabels'
 import type { Config } from '@/types/engine'
 
 // The collapsible advanced grid (spec section 4): world-shaping numbers
@@ -17,10 +18,10 @@ interface NumberFieldDef {
 }
 
 const numberFields: NumberFieldDef[] = [
-  { field: 'numStudents', label: 'Students', min: 2, step: 1 },
-  { field: 'edgesPerNode', label: 'Friends per student', min: 1, step: 1 },
-  { field: 'triangleProb', label: 'Clique tendency', min: 0, step: 0.05 },
-  { field: 'origin', label: 'First poster', min: 0, step: 1 },
+  { field: 'numStudents', label: CONFIG_FIELD_LABELS.numStudents, min: 2, step: 1 },
+  { field: 'edgesPerNode', label: CONFIG_FIELD_LABELS.edgesPerNode, min: 1, step: 1 },
+  { field: 'triangleProb', label: CONFIG_FIELD_LABELS.triangleProb, min: 0, step: 0.05 },
+  { field: 'origin', label: CONFIG_FIELD_LABELS.origin, min: 0, step: 1 },
 ]
 
 interface SeedFieldDef {
@@ -29,9 +30,9 @@ interface SeedFieldDef {
 }
 
 const seedFields: SeedFieldDef[] = [
-  { field: 'graphSeed', label: 'Friendship network' },
-  { field: 'thresholdSeed', label: 'Who resists' },
-  { field: 'educationSeed', label: 'Random picks' },
+  { field: 'graphSeed', label: CONFIG_FIELD_LABELS.graphSeed },
+  { field: 'thresholdSeed', label: CONFIG_FIELD_LABELS.thresholdSeed },
+  { field: 'educationSeed', label: CONFIG_FIELD_LABELS.educationSeed },
 ]
 
 // The engine's 400 message names the offending Go/JSON field; mark it.
diff --git a/web/src/components/PanelEditorPopover.vue b/web/src/components/PanelEditorPopover.vue
new file mode 100644
index 0000000..3645de9
--- /dev/null
+++ b/web/src/components/PanelEditorPopover.vue
@@ -0,0 +1,297 @@
+<script setup lang="ts">
+import { computed, onBeforeUnmount, onMounted, ref } from 'vue'
+import { useSimStore } from '@/composables/useSimStore'
+import { CONFIG_FIELD_LABELS, STRATEGY_LABELS } from '@/lib/fieldLabels'
+import type { PanelSpec } from '@/presets/types'
+import type { Config } from '@/types/engine'
+
+// The per-panel config diff editor (spec 5.7): the label is renamed
+// inline in the header, the strategy is a select, and every Config field
+// is a row showing the base value. Typing a different value creates an
+// override (highlighted row, reset icon); typing the base value back
+// removes it. Apply follows the store's debounced single-panel rerun.
+
+const props = defineProps<{ panel: PanelSpec; focusLabel?: boolean }>()
+const emit = defineEmits<{ close: [] }>()
+
+const store = useSimStore()
+
+const popover = ref<HTMLElement | null>(null)
+const labelInput = ref<HTMLInputElement | null>(null)
+
+const fieldNames = Object.keys(store.state.base) as (keyof Config)[]
+
+const offendingField = computed(() => {
+  const validationError = store.state.validationError
+  if (!validationError) return null
+  return fieldNames.find((field) => validationError.includes(field)) ?? null
+})
+
+function isOverridden(field: keyof Config): boolean {
+  return field in props.panel.overrides
+}
+
+function effectiveValue(field: keyof Config): number {
+  return props.panel.overrides[field] ?? store.state.base[field]
+}
+
+function setOverride(field: keyof Config, event: Event) {
+  const nextValue = (event.target as HTMLInputElement).valueAsNumber
+  if (Number.isFinite(nextValue)) store.setPanelOverride(props.panel.id, field, nextValue)
+}
+
+function rename(event: Event) {
+  const label = (event.target as HTMLInputElement).value.trim()
+  if (label) store.renamePanel(props.panel.id, label)
+}
+
+function onKeydown(event: KeyboardEvent) {
+  if (event.key === 'Escape') emit('close')
+}
+
+function onPointerDown(event: PointerEvent) {
+  if (popover.value?.contains(event.target as Node)) return
+  emit('close')
+}
+
+onMounted(() => {
+  if (props.focusLabel) {
+    labelInput.value?.focus()
+    labelInput.value?.select()
+  } else {
+    popover.value?.querySelector('select')?.focus()
+  }
+  document.addEventListener('keydown', onKeydown)
+  document.addEventListener('pointerdown', onPointerDown, true)
+})
+
+onBeforeUnmount(() => {
+  document.removeEventListener('keydown', onKeydown)
+  document.removeEventListener('pointerdown', onPointerDown, true)
+})
+</script>
+
+<template>
+  <div
+    ref="popover"
+    class="editor"
+    role="dialog"
+    :aria-label="`Edit scenario ${panel.label}`"
+    tabindex="-1"
+  >
+    <div class="head">
+      <input
+        ref="labelInput"
+        class="label-input"
+        type="text"
+        :value="panel.label"
+        aria-label="Scenario name"
+        @change="rename"
+      />
+      <button class="close" type="button" aria-label="Close editor" @click="emit('close')">
+        <svg class="ic" viewBox="0 0 24 24"><path d="M6 6l12 12M18 6L6 18" /></svg>
+      </button>
+    </div>
+
+    <p v-if="store.state.validationError" class="invalid-note" role="alert">
+      {{ store.state.validationError }}
+    </p>
+
+    <label class="row strategy">
+      <span class="rl">Strategy</span>
+      <select
+        :value="panel.strategy"
+        @change="store.setPanelStrategy(panel.id, ($event.target as HTMLSelectElement).value)"
+      >
+        <option v-for="(label, strategy) in STRATEGY_LABELS" :key="strategy" :value="strategy">
+          {{ label }}
+        </option>
+      </select>
+    </label>
+
+    <div class="rows">
+      <div
+        v-for="field in fieldNames"
+        :key="field"
+        class="row"
+        :class="{ overridden: isOverridden(field), invalid: offendingField === field }"
+      >
+        <label class="rl" :for="`${panel.id}-${field}`">{{ CONFIG_FIELD_LABELS[field] }}</label>
+        <span class="base" :class="{ hidden: !isOverridden(field) }"
+          >base {{ store.state.base[field] }}</span
+        >
+        <input
+          :id="`${panel.id}-${field}`"
+          type="number"
+          :value="effectiveValue(field)"
+          :aria-invalid="offendingField === field || undefined"
+          @change="setOverride(field, $event)"
+        />
+        <button
+          v-if="isOverridden(field)"
+          class="reset"
+          type="button"
+          :aria-label="`Reset ${CONFIG_FIELD_LABELS[field]} to the base value`"
+          @click="store.clearPanelOverride(panel.id, field)"
+        >
+          <svg class="ic" viewBox="0 0 24 24"><path d="M3 12a9 9 0 1 0 2.6-6.3M5 3v4h4" /></svg>
+        </button>
+        <span v-else class="reset-spacer" aria-hidden="true" />
+      </div>
+    </div>
+  </div>
+</template>
+
+<style scoped>
+.editor {
+  position: absolute;
+  top: 44px;
+  right: 12px;
+  z-index: 25;
+  width: min(300px, calc(100% - 24px));
+  background: var(--surface);
+  border: 1px solid var(--border);
+  border-radius: 14px;
+  box-shadow: var(--shadow-lift);
+  padding: 12px 14px 14px;
+}
+
+.head {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.label-input {
+  flex: 1;
+  min-width: 0;
+  font: 600 13.5px/1.4 inherit;
+  font-family: inherit;
+  color: var(--ink);
+  background: var(--bg);
+  border: 1px solid var(--border-soft);
+  border-radius: 8px;
+  padding: 5px 9px;
+}
+
+.close {
+  width: 28px;
+  height: 28px;
+  border: none;
+  background: none;
+  border-radius: 8px;
+  color: var(--ink-3);
+  display: grid;
+  place-items: center;
+  cursor: pointer;
+  flex: none;
+}
+
+.close:hover {
+  background: var(--bg);
+  color: var(--ink);
+}
+
+.close svg.ic {
+  width: 14px;
+  height: 14px;
+}
+
+.invalid-note {
+  margin-top: 8px;
+  font-size: 12px;
+  font-weight: 500;
+  color: var(--spread);
+}
+
+.rows {
+  margin-top: 4px;
+}
+
+.row {
+  display: flex;
+  align-items: center;
+  gap: 7px;
+  padding: 5px 6px;
+  border-radius: 8px;
+  font-size: 12.5px;
+}
+
+.row.strategy {
+  margin-top: 10px;
+  padding: 5px 6px;
+}
+
+.row.overridden {
+  background: var(--edu-soft);
+}
+
+.row.invalid {
+  outline: 1px solid var(--spread);
+}
+
+.rl {
+  flex: 1;
+  min-width: 0;
+  color: var(--ink-3);
+  font-weight: 500;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.base {
+  font-size: 11px;
+  color: var(--ink-4);
+  white-space: nowrap;
+}
+
+.base.hidden {
+  visibility: hidden;
+}
+
+select {
+  font: 600 12.5px/1.4 inherit;
+  font-family: inherit;
+  color: var(--ink-2);
+  background: var(--bg);
+  border: 1px solid var(--border-soft);
+  border-radius: 8px;
+  padding: 4px 8px;
+}
+
+input[type='number'] {
+  width: 72px;
+  font: 600 12.5px/1.4 inherit;
+  font-family: inherit;
+  color: var(--ink-2);
+  background: var(--bg);
+  border: 1px solid var(--border-soft);
+  border-radius: 8px;
+  padding: 4px 8px;
+  text-align: right;
+}
+
+.reset {
+  width: 22px;
+  height: 22px;
+  border: none;
+  background: none;
+  border-radius: 6px;
+  color: var(--edu);
+  display: grid;
+  place-items: center;
+  cursor: pointer;
+  flex: none;
+}
+
+.reset svg.ic {
+  width: 12px;
+  height: 12px;
+}
+
+.reset-spacer {
+  width: 22px;
+  flex: none;
+}
+</style>
diff --git a/web/src/components/PanelMenu.vue b/web/src/components/PanelMenu.vue
new file mode 100644
index 0000000..fc72e10
--- /dev/null
+++ b/web/src/components/PanelMenu.vue
@@ -0,0 +1,107 @@
+<script setup lang="ts">
+import { onBeforeUnmount, onMounted, ref } from 'vue'
+
+// The kebab dropdown (spec 5.7). Items come from the panel; the menu
+// handles roving focus (arrows), Esc, and outside clicks. The opener
+// restores focus on close.
+
+export interface PanelMenuItem {
+  key: string
+  label: string
+  disabled?: boolean
+}
+
+const props = defineProps<{ items: PanelMenuItem[]; anchor: HTMLElement | null }>()
+const emit = defineEmits<{ select: [key: string]; close: [] }>()
+
+const menu = ref<HTMLElement | null>(null)
+
+function menuButtons(): HTMLButtonElement[] {
+  return Array.from(menu.value?.querySelectorAll('button:not(:disabled)') ?? [])
+}
+
+function onKeydown(event: KeyboardEvent) {
+  if (event.key === 'Escape') {
+    emit('close')
+    return
+  }
+  if (event.key !== 'ArrowDown' && event.key !== 'ArrowUp') return
+  event.preventDefault()
+  const buttons = menuButtons()
+  if (buttons.length === 0) return
+  const activeIndex = buttons.findIndex((button) => button === document.activeElement)
+  const offset = event.key === 'ArrowDown' ? 1 : -1
+  const nextIndex = (activeIndex + offset + buttons.length) % buttons.length
+  buttons[nextIndex]?.focus()
+}
+
+function onPointerDown(event: PointerEvent) {
+  const target = event.target as Node
+  if (menu.value?.contains(target)) return
+  if (props.anchor?.contains(target)) return
+  emit('close')
+}
+
+onMounted(() => {
+  menuButtons()[0]?.focus()
+  document.addEventListener('pointerdown', onPointerDown, true)
+})
+
+onBeforeUnmount(() => {
+  document.removeEventListener('pointerdown', onPointerDown, true)
+})
+</script>
+
+<template>
+  <div ref="menu" class="menu" role="menu" @keydown="onKeydown">
+    <button
+      v-for="item in items"
+      :key="item.key"
+      type="button"
+      role="menuitem"
+      :disabled="item.disabled"
+      @click="emit('select', item.key)"
+    >
+      {{ item.label }}
+    </button>
+  </div>
+</template>
+
+<style scoped>
+.menu {
+  position: absolute;
+  top: calc(100% + 6px);
+  right: 0;
+  z-index: 25;
+  min-width: 150px;
+  background: var(--surface);
+  border: 1px solid var(--border);
+  border-radius: 12px;
+  box-shadow: var(--shadow-lift);
+  padding: 5px;
+  display: flex;
+  flex-direction: column;
+}
+
+button {
+  text-align: left;
+  font-size: 13.5px;
+  font-weight: 500;
+  color: var(--ink-2);
+  background: none;
+  border: none;
+  border-radius: 8px;
+  padding: 7px 10px;
+  cursor: pointer;
+}
+
+button:hover:not(:disabled) {
+  background: var(--bg);
+  color: var(--ink);
+}
+
+button:disabled {
+  color: var(--ink-4);
+  cursor: default;
+}
+</style>
diff --git a/web/src/components/ResultsTable.vue b/web/src/components/ResultsTable.vue
index 19bc416..5f7e08b 100644
--- a/web/src/components/ResultsTable.vue
+++ b/web/src/components/ResultsTable.vue
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import { STRATEGY_LABELS } from '@/lib/fieldLabels'
 import { formatPct } from '@/lib/format'
 import type { PanelSpec } from '@/presets/types'
 import type { Config, Result } from '@/types/engine'
@@ -13,12 +14,6 @@ const props = defineProps<{
   base: Config
 }>()
 
-const strategyLabels: Record<string, string> = {
-  none: 'None',
-  random: 'Random',
-  'most-connected': 'Most connected',
-}
-
 function numStudentsFor(panel: PanelSpec): number {
   return panel.overrides.numStudents ?? props.base.numStudents
 }
@@ -48,7 +43,7 @@ function numStudentsFor(panel: PanelSpec): number {
         <tr v-for="panel in panels" :key="panel.id">
           <th scope="row">{{ panel.label }}</th>
           <template v-if="resultsByPanelId[panel.id]">
-            <td>{{ strategyLabels[panel.strategy] ?? panel.strategy }}</td>
+            <td>{{ STRATEGY_LABELS[panel.strategy] ?? panel.strategy }}</td>
             <td>{{ resultsByPanelId[panel.id]!.educated.length }}</td>
             <td>{{ resultsByPanelId[panel.id]!.numReached }} / {{ numStudentsFor(panel) }}</td>
             <td>{{ formatPct(resultsByPanelId[panel.id]!.reachedPct) }}</td>
diff --git a/web/src/components/ScenarioPanel.vue b/web/src/components/ScenarioPanel.vue
index 6308752..ce6cdd7 100644
--- a/web/src/components/ScenarioPanel.vue
+++ b/web/src/components/ScenarioPanel.vue
@@ -1,15 +1,59 @@
 <script setup lang="ts">
-import { computed } from 'vue'
+import { computed, ref } from 'vue'
 import NetworkView from './NetworkView.vue'
+import PanelEditorPopover from './PanelEditorPopover.vue'
+import PanelMenu, { type PanelMenuItem } from './PanelMenu.vue'
 import { useSimStore } from '@/composables/useSimStore'
 import { roundPct } from '@/lib/format'
 import { reachedCountAtRound } from '@/lib/reach'
-import type { PanelSpec } from '@/presets/types'
+import { MAX_PANELS, type PanelSpec } from '@/presets/types'
 
 const props = defineProps<{ panel: PanelSpec; accent: string }>()
 
 const store = useSimStore()
 
+const menuOpen = ref(false)
+const focusLabelOnOpen = ref(false)
+const kebabButton = ref<HTMLButtonElement | null>(null)
+
+const editing = computed(() => store.state.editingPanelId === props.panel.id)
+const failed = computed(() => store.state.failedPanelIds.has(props.panel.id))
+
+const menuItems = computed<PanelMenuItem[]>(() => [
+  { key: 'edit', label: 'Edit' },
+  { key: 'rename', label: 'Rename' },
+  { key: 'duplicate', label: 'Duplicate', disabled: store.state.panels.length >= MAX_PANELS },
+  { key: 'remove', label: 'Remove', disabled: store.state.panels.length <= 1 },
+])
+
+function onMenuSelect(itemKey: string) {
+  menuOpen.value = false
+  switch (itemKey) {
+    case 'edit':
+    case 'rename':
+      focusLabelOnOpen.value = itemKey === 'rename'
+      store.state.editingPanelId = props.panel.id
+      break
+    case 'duplicate':
+      store.duplicatePanel(props.panel.id)
+      kebabButton.value?.focus()
+      break
+    case 'remove':
+      store.removePanel(props.panel.id)
+      break
+  }
+}
+
+function closeMenu() {
+  menuOpen.value = false
+  kebabButton.value?.focus()
+}
+
+function closeEditor() {
+  store.state.editingPanelId = null
+  kebabButton.value?.focus()
+}
+
 const result = computed(() => store.state.resultsByPanelId[props.panel.id])
 const numStudents = computed(() => store.effectiveConfig(props.panel).numStudents)
 
@@ -50,10 +94,36 @@ const dimmed = computed(() => store.state.runState === 'running' && result.value
     <div class="head">
       <span class="swatch" :style="{ background: accent }" aria-hidden="true" />
       <span class="label">{{ panel.label }}</span>
-      <button class="kebab" type="button" disabled title="Scenario menu arrives in a later slice">
+      <button
+        ref="kebabButton"
+        class="kebab"
+        type="button"
+        aria-haspopup="menu"
+        :aria-expanded="menuOpen"
+        :aria-label="`Scenario menu for ${panel.label}`"
+        @click="menuOpen = !menuOpen"
+      >
         <svg class="ic" viewBox="0 0 24 24"><path d="M12 6h.01M12 12h.01M12 18h.01" /></svg>
+        <span
+          v-if="failed"
+          class="fail-dot"
+          :title="`The last run of ${panel.label} failed; showing its previous result`"
+        />
       </button>
+      <PanelMenu
+        v-if="menuOpen"
+        :items="menuItems"
+        :anchor="kebabButton"
+        @select="onMenuSelect"
+        @close="closeMenu"
+      />
     </div>
+    <PanelEditorPopover
+      v-if="editing"
+      :panel="panel"
+      :focus-label="focusLabelOnOpen"
+      @close="closeEditor"
+    />
     <template v-if="result">
       <div class="pct" :class="tone">{{ roundPct(reachedPctNow) }}<small>%</small></div>
       <div class="meta">
@@ -104,6 +174,7 @@ const dimmed = computed(() => store.state.runState === 'running' && result.value
   display: flex;
   align-items: center;
   gap: 8px;
+  position: relative;
 }
 
 .swatch {
@@ -134,10 +205,23 @@ const dimmed = computed(() => store.state.runState === 'running' && result.value
   border-radius: 8px;
   display: grid;
   place-items: center;
+  cursor: pointer;
+  position: relative;
 }
 
-.kebab:disabled {
-  cursor: default;
+.kebab:hover {
+  background: var(--bg);
+  color: var(--ink);
+}
+
+.fail-dot {
+  position: absolute;
+  top: 2px;
+  right: 2px;
+  width: 7px;
+  height: 7px;
+  border-radius: 50%;
+  background: var(--spread);
 }
 
 .pct {
diff --git a/web/src/components/ScenarioToolbar.vue b/web/src/components/ScenarioToolbar.vue
index 3d34ef9..475f3f0 100644
--- a/web/src/components/ScenarioToolbar.vue
+++ b/web/src/components/ScenarioToolbar.vue
@@ -11,6 +11,12 @@ const atPanelCap = computed(() => store.state.panels.length >= MAX_PANELS)
 const refreshing = computed(
   () => store.state.runState === 'running' && Object.keys(store.state.resultsByPanelId).length > 0,
 )
+
+// Spec 5.6: a new panel opens its editor right away.
+function addScenario() {
+  const addedPanel = store.addPanel()
+  if (addedPanel) store.state.editingPanelId = addedPanel.id
+}
 </script>
 
 <template>
@@ -27,7 +33,7 @@ const refreshing = computed(
       type="button"
       :disabled="atPanelCap"
       :title="atPanelCap ? 'Maximum 6 scenarios' : undefined"
-      @click="store.addPanel()"
+      @click="addScenario()"
     >
       <svg class="ic" viewBox="0 0 24 24"><path d="M12 6v12M6 12h12" /></svg>
       Add scenario
diff --git a/web/src/composables/__tests__/useSimStore.spec.ts b/web/src/composables/__tests__/useSimStore.spec.ts
index 8c219de..dea9086 100644
--- a/web/src/composables/__tests__/useSimStore.spec.ts
+++ b/web/src/composables/__tests__/useSimStore.spec.ts
@@ -152,11 +152,14 @@ describe('useSimStore runs', () => {
     expect(store.state.errorMessage).toBe('fetch failed')
     expect(store.state.validationError).toBeNull()
     expect(store.state.resultsByPanelId).toEqual(goodResults)
+    // Every panel in the failed run gets the rose kebab dot.
+    expect(store.state.failedPanelIds.size).toBe(3)
 
     runScenarioMock.mockImplementation(async (request) => fakeResponse(request))
     await store.retry()
     expect(store.state.runState).toBe('idle')
     expect(store.state.errorMessage).toBeNull()
+    expect(store.state.failedPanelIds.size).toBe(0)
   })
 
   it('routes a 400 to validationError instead of the banner', async () => {
diff --git a/web/src/composables/useSimStore.ts b/web/src/composables/useSimStore.ts
index 47168d2..28360af 100644
--- a/web/src/composables/useSimStore.ts
+++ b/web/src/composables/useSimStore.ts
@@ -28,6 +28,8 @@ export interface SimState {
   playing: boolean
   speed: PlaybackSpeed
   focusPanelId: string | null
+  editingPanelId: string | null // panel whose editor popover is open
+  failedPanelIds: Set<string> // panels whose latest request failed (rose kebab dot)
   hoveredNode: number | null
   runState: RunState
   errorMessage: string | null // network/server failure, shown in the ErrorBanner
@@ -54,6 +56,8 @@ export function createSimStore(preset: StudyPreset = deepfakeSchoolPreset) {
     playing: false,
     speed: 1,
     focusPanelId: null,
+    editingPanelId: null,
+    failedPanelIds: new Set<string>(),
     hoveredNode: null,
     runState: 'idle',
     errorMessage: null,
@@ -135,6 +139,10 @@ export function createSimStore(preset: StudyPreset = deepfakeSchoolPreset) {
       // Keep the last good results untouched; only the latest run may
       // surface its error.
       if (!isLatestRun) return
+      settled.forEach((outcome, index) => {
+        const panel = targets[index]
+        if (panel && outcome.status === 'rejected') state.failedPanelIds.add(panel.id)
+      })
       const reason: unknown = firstFailure.reason
       state.runState = 'error'
       if (reason instanceof ApiError && reason.status === 400) {
@@ -153,6 +161,7 @@ export function createSimStore(preset: StudyPreset = deepfakeSchoolPreset) {
       if (outcome?.status !== 'fulfilled') return
       state.resultsByPanelId[panel.id] = outcome.value.result
       state.edgesByGraphHash[graphKey(outcome.value.config)] = outcome.value.edges
+      state.failedPanelIds.delete(panel.id)
     })
 
     if (!isLatestRun) return
@@ -213,7 +222,9 @@ export function createSimStore(preset: StudyPreset = deepfakeSchoolPreset) {
     if (index < 0) return
     state.panels.splice(index, 1)
     delete state.resultsByPanelId[panelId]
+    state.failedPanelIds.delete(panelId)
     if (state.focusPanelId === panelId) state.focusPanelId = null
+    if (state.editingPanelId === panelId) state.editingPanelId = null
     syncToUrl()
   }
 
diff --git a/web/src/lib/fieldLabels.ts b/web/src/lib/fieldLabels.ts
new file mode 100644
index 0000000..153c82e
--- /dev/null
+++ b/web/src/lib/fieldLabels.ts
@@ -0,0 +1,21 @@
+import type { Config, Strategy } from '@/types/engine'
+
+// One human name per Config field, shared by the controls card and the
+// panel editor so the same lever never appears under two names.
+export const CONFIG_FIELD_LABELS: Record<keyof Config, string> = {
+  numStudents: 'Students',
+  edgesPerNode: 'Friends per student',
+  triangleProb: 'Clique tendency',
+  forwardProb: 'Chance to forward',
+  numEducated: 'Education budget',
+  origin: 'First poster',
+  graphSeed: 'Friendship network',
+  thresholdSeed: 'Who resists',
+  educationSeed: 'Random picks',
+}
+
+export const STRATEGY_LABELS: Record<Strategy, string> = {
+  none: 'None',
+  random: 'Random',
+  'most-connected': 'Most connected',
+}