Add collapsible primary UI sections (ticket 035)

Log viewer (FilterBar+LogTimeline+LogPreview), Params, Metrics, and
Dashboards can each be collapsed/expanded via a toggle next to their
existing help icon. Collapsed state persists per-section in
localStorage (ottyl.collapsedSections) and content is hidden with the
`hidden` attribute rather than unmounted, so in-progress form state
(a half-filled Metrics/Params form, in-progress Dashboards panel
edits) survives a collapse/expand cycle.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XFUNZwCvz3kcod3352ZR2o

webapp/src/App.tsx

@@ -7,6 +7,7 @@ import { Params } from './components/Params'
 import { Metrics } from './components/Metrics'
 import { Dashboards } from './components/Dashboards'
 import { Alerts } from './components/Alerts'
+import { CollapseToggle, useSectionCollapsed } from './components/CollapsibleSection'
 import {
   fetchLogs,
   fetchParamDeclarations,
@@ -30,6 +31,7 @@ export default function App() {
   const [activePreset, setActivePreset] = useState<TimeRangePresetId | null>('all')
   const [filter, setFilter] = useState('')
   const [filterError, setFilterError] = useState<string | null>(null)
+  const [logViewerCollapsed, setLogViewerCollapsed] = useSectionCollapsed('log-viewer')
 
   // Read from inside the poll loop below without making it a dependency —
   // a rolling preset's own re-resolution (ticket 024) updates `range`, and
@@ -123,15 +125,24 @@ export default function App() {
       <div className="flex h-screen w-screen overflow-hidden">
         <NavMenu stats={stats} />
         <div className="flex min-w-0 flex-1 flex-col">
-          <FilterBar value={filter} onChange={setFilter} error={filterError} />
-          <LogTimeline
-            buckets={buckets}
-            range={range}
-            onSelectRange={handleManualRangeSelect}
-            activePreset={activePreset}
-            onSelectPreset={selectPreset}
+          <FilterBar
+            value={filter}
+            onChange={setFilter}
+            error={filterError}
+            collapseToggle={
+              <CollapseToggle collapsed={logViewerCollapsed} onToggle={() => setLogViewerCollapsed(!logViewerCollapsed)} />
+            }
           />
-          <LogPreview logs={logs} params={params} />
+          <div className="flex min-h-0 flex-1 flex-col" hidden={logViewerCollapsed}>
+            <LogTimeline
+              buckets={buckets}
+              range={range}
+              onSelectRange={handleManualRangeSelect}
+              activePreset={activePreset}
+              onSelectPreset={selectPreset}
+            />
+            <LogPreview logs={logs} params={params} />
+          </div>
           <Params params={params} onDeclared={loadParams} />
           <Metrics range={range} />
           <Dashboards range={range} />

webapp/src/components/CollapsibleSection.tsx

@@ -0,0 +1,59 @@
+import { useState } from 'react'
+
+/// localStorage key for which of the four primary sections (log viewer,
+/// params, metrics, dashboards) are collapsed (ticket 035). Mirrors
+/// LogPreview's VISIBLE_PARAM_COLUMNS_STORAGE_KEY pattern — one key holding
+/// a record of section id -> collapsed.
+const COLLAPSED_SECTIONS_STORAGE_KEY = 'ottyl.collapsedSections'
+
+function loadCollapsedSections(): Record<string, boolean> {
+  try {
+    const raw = localStorage.getItem(COLLAPSED_SECTIONS_STORAGE_KEY)
+    if (!raw) return {}
+    const parsed = JSON.parse(raw)
+    return parsed && typeof parsed === 'object' ? parsed : {}
+  } catch {
+    return {}
+  }
+}
+
+function saveCollapsedSections(sections: Record<string, boolean>) {
+  try {
+    localStorage.setItem(COLLAPSED_SECTIONS_STORAGE_KEY, JSON.stringify(sections))
+  } catch {
+    // best-effort — a private browsing mode or full storage just means the
+    // collapsed state won't persist across reloads.
+  }
+}
+
+/// Persists a section's collapsed state across reloads. Deliberately
+/// returns only the boolean + setter — callers keep rendering their
+/// subtree, just hide it with CSS (`hidden`), so collapsing never unmounts
+/// in-progress form state.
+export function useSectionCollapsed(sectionId: string): [boolean, (next: boolean) => void] {
+  const [collapsed, setCollapsedState] = useState(() => loadCollapsedSections()[sectionId] ?? false)
+
+  function setCollapsed(next: boolean) {
+    setCollapsedState(next)
+    const all = loadCollapsedSections()
+    all[sectionId] = next
+    saveCollapsedSections(all)
+  }
+
+  return [collapsed, setCollapsed]
+}
+
+export function CollapseToggle({ collapsed, onToggle }: { collapsed: boolean; onToggle: () => void }) {
+  return (
+    <button
+      type="button"
+      onClick={onToggle}
+      title={collapsed ? 'Expand section' : 'Collapse section'}
+      aria-label={collapsed ? 'Expand section' : 'Collapse section'}
+      aria-expanded={!collapsed}
+      className="flex h-4 w-4 shrink-0 items-center justify-center rounded-full border border-border-soft text-[10px] leading-none text-text-faint hover:border-border-strong hover:text-text-secondary"
+    >
+      {collapsed ? '▸' : '▾'}
+    </button>
+  )
+}

webapp/src/components/Dashboards.tsx

@@ -14,6 +14,7 @@ import {
   type Panel,
   type PromqlSeries,
 } from '../lib/api'
+import { CollapseToggle, useSectionCollapsed } from './CollapsibleSection'
 import { HelpIcon } from './HelpIcon'
 
 const CHART_TYPES: ChartType[] = ['line', 'bar', 'pie']
@@ -113,6 +114,7 @@ export function Dashboards({ range }: { range: TimeRange | null }) {
   // nothing actually changed (e.g. re-selecting the same dashboard, or the
   // re-render that follows a successful save itself).
   const lastSavedRef = useRef<string | null>(null)
+  const [collapsed, setCollapsed] = useSectionCollapsed('dashboards')
 
   async function loadDashboards(profileName: string, selectAfterLoad?: string) {
     try {
@@ -231,6 +233,7 @@ export function Dashboards({ range }: { range: TimeRange | null }) {
     return (
       <div className="flex items-center gap-1.5 border-b border-border p-3 text-xs text-text-faint">
         <HelpIcon sectionId="dashboards" label="Help: Dashboards" />
+        <CollapseToggle collapsed={collapsed} onToggle={() => setCollapsed(!collapsed)} />
         Dashboards — activate a profile (see the settings menu) to create and save dashboards.
       </div>
     )
@@ -240,12 +243,13 @@ export function Dashboards({ range }: { range: TimeRange | null }) {
     <div className="border-b border-border p-3 text-sm">
       <div className="mb-2 flex items-center gap-1.5 text-xs text-text-subtle">
         <HelpIcon sectionId="dashboards" label="Help: Dashboards" />
+        <CollapseToggle collapsed={collapsed} onToggle={() => setCollapsed(!collapsed)} />
         Dashboards — profile "{activeProfile}"
       </div>
-      {error && (
+      {error && !collapsed && (
         <div className="mb-2 rounded border border-danger-border bg-danger-bg/50 px-2 py-1 text-xs text-danger-text">{error}</div>
       )}
-      <div className="flex gap-4">
+      <div className="flex gap-4" hidden={collapsed}>
         <div className="w-56 shrink-0 space-y-3">
           <form onSubmit={handleCreateDashboard} className="flex gap-1">
             <input

webapp/src/components/FilterBar.tsx

@@ -1,3 +1,4 @@
+import type { ReactNode } from 'react'
 import { useState } from 'react'
 import { HelpIcon } from './HelpIcon'
 
@@ -18,10 +19,12 @@ export function FilterBar({
   value,
   onChange,
   error,
+  collapseToggle,
 }: {
   value: string
   onChange: (value: string) => void
   error?: string | null
+  collapseToggle?: ReactNode
 }) {
   const [draft, setDraft] = useState(value)
 
@@ -35,6 +38,7 @@ export function FilterBar({
     >
       <div className="flex items-center gap-2">
         <HelpIcon sectionId="filtering" label="Help: Filtering" />
+        {collapseToggle}
         <input
           className={queryInputClassName}
           placeholder='regex("error") and sequence<5 or timestamp>12:00'

webapp/src/components/Metrics.tsx

@@ -10,6 +10,7 @@ import {
   type MetricDeclaration,
   type MetricParamMatcher,
 } from '../lib/api'
+import { CollapseToggle, useSectionCollapsed } from './CollapsibleSection'
 import { HelpIcon } from './HelpIcon'
 
 const EMPTY_MATCHER: MetricParamMatcher = { param_name: '', capture_group: '', kind: 'string' }
@@ -82,6 +83,7 @@ export function Metrics({ range }: { range: TimeRange | null }) {
   const [matchers, setMatchers] = useState<MetricParamMatcher[]>([{ ...EMPTY_MATCHER }])
   const [submitError, setSubmitError] = useState<string | null>(null)
   const [submitting, setSubmitting] = useState(false)
+  const [collapsed, setCollapsed] = useSectionCollapsed('metrics')
 
   async function loadMetrics() {
     try {
@@ -160,8 +162,9 @@ export function Metrics({ range }: { range: TimeRange | null }) {
       <div className="mb-2 flex items-center gap-1.5 text-xs text-text-subtle">
         Metrics
         <HelpIcon sectionId="metrics" label="Help: Metrics" />
+        <CollapseToggle collapsed={collapsed} onToggle={() => setCollapsed(!collapsed)} />
       </div>
-      <div className="flex gap-4">
+      <div className="flex gap-4" hidden={collapsed}>
         <form onSubmit={handleSubmit} className="w-80 shrink-0 space-y-2">
           <div>
             <label className="mb-1 block text-xs text-text-subtle">Name</label>

webapp/src/components/Params.tsx

@@ -1,5 +1,6 @@
 import { useState } from 'react'
 import { ApiError, declareParam, type ParamDeclaration } from '../lib/api'
+import { CollapseToggle, useSectionCollapsed } from './CollapsibleSection'
 import { HelpIcon } from './HelpIcon'
 
 const EMPTY_KIND: ParamDeclaration['kind'] = 'string'
@@ -11,6 +12,7 @@ export function Params({ params, onDeclared }: { params: ParamDeclaration[]; onD
   const [kind, setKind] = useState<ParamDeclaration['kind']>(EMPTY_KIND)
   const [submitError, setSubmitError] = useState<string | null>(null)
   const [submitting, setSubmitting] = useState(false)
+  const [collapsed, setCollapsed] = useSectionCollapsed('params')
 
   async function handleSubmit(e: React.FormEvent) {
     e.preventDefault()
@@ -35,8 +37,9 @@ export function Params({ params, onDeclared }: { params: ParamDeclaration[]; onD
       <div className="mb-2 flex items-center gap-1.5 text-xs text-text-subtle">
         Params
         <HelpIcon sectionId="parameters" label="Help: Params" />
+        <CollapseToggle collapsed={collapsed} onToggle={() => setCollapsed(!collapsed)} />
       </div>
-      <div className="flex gap-4">
+      <div className="flex gap-4" hidden={collapsed}>
         <form onSubmit={handleSubmit} className="w-80 shrink-0 space-y-2">
           <div>
             <label className="mb-1 block text-xs text-text-subtle">Name</label>