Add contextual "?" help icons linking into Docs (ticket 021)

New HelpIcon component + a DocsNavProvider context (webapp/src/lib/docsNav.tsx)
let any component request "open Docs to section X", bumping a nonce each
time so a repeat click re-triggers even if Docs is already open to that
section. NavMenu forwards that request into DocsPanel as a `target` prop,
which expands the right accordion section, scrolls it into view, and
flashes it (a brief accent-tinted background/border, settling back after
1.2s) — verified visually with a live server + Playwright. Opening Docs via
the plain NavMenu button explicitly clears any pending target, so that path
is unchanged: no forced section, no flash.

Added a "?" icon to FilterBar, LogTimeline, LogPreview, Metrics, Dashboards,
and NavMenu's own Settings/Presets panels, plus new Docs sections for
Timeline, Log preview, Settings, and Presets (previously undocumented).

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

webapp/src/App.tsx

@@ -6,6 +6,7 @@ import { LogPreview } from './components/LogPreview'
 import { Metrics } from './components/Metrics'
 import { Dashboards } from './components/Dashboards'
 import { fetchLogs, fetchStats, fetchTimeline, type LogEntry, type Stats, type TimelineBucket } from './lib/api'
+import { DocsNavProvider } from './lib/docsNav'
 
 const POLL_MS = 2000
 
@@ -49,6 +50,7 @@ export default function App() {
   }, [range, filter])
 
   return (
+    <DocsNavProvider>
       <div className="flex h-screen w-screen overflow-hidden">
         <NavMenu stats={stats} />
         <div className="flex min-w-0 flex-1 flex-col">
@@ -59,5 +61,6 @@ export default function App() {
           <Dashboards range={range} />
         </div>
       </div>
+    </DocsNavProvider>
   )
 }

webapp/src/components/Dashboards.tsx

@@ -14,6 +14,7 @@ import {
   type Panel,
   type PromqlSeries,
 } from '../lib/api'
+import { HelpIcon } from './HelpIcon'
 
 const CHART_TYPES: ChartType[] = ['line', 'bar', 'pie']
 
@@ -168,7 +169,8 @@ export function Dashboards({ range }: { range: TimeRange | null }) {
 
   if (!activeProfile) {
     return (
-      <div className="border-b border-border p-3 text-xs text-text-faint">
+      <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" />
         Dashboards — activate a profile (see the settings menu) to create and save dashboards.
       </div>
     )
@@ -176,7 +178,10 @@ export function Dashboards({ range }: { range: TimeRange | null }) {
 
   return (
     <div className="border-b border-border p-3 text-sm">
-      <div className="mb-2 text-xs text-text-subtle">Dashboards — profile "{activeProfile}"</div>
+      <div className="mb-2 flex items-center gap-1.5 text-xs text-text-subtle">
+        <HelpIcon sectionId="dashboards" label="Help: Dashboards" />
+        Dashboards — profile "{activeProfile}"
+      </div>
       {error && (
         <div className="mb-2 rounded border border-danger-border bg-danger-bg/50 px-2 py-1 text-xs text-danger-text">{error}</div>
       )}

webapp/src/components/Docs.tsx

@@ -1,4 +1,5 @@
-import { useState, type ReactNode } from 'react'
+import { useEffect, useRef, useState, type ReactNode } from 'react'
+import type { DocsTarget } from '../lib/docsNav'
 
 /// One accordion section: a title plus its body, rendered as plain JSX so
 /// each page can mix prose, lists, and inline code without pulling in a
@@ -122,6 +123,32 @@ const SECTIONS: DocSection[] = [
       </div>
     ),
   },
+  {
+    id: 'timeline',
+    title: 'Timeline',
+    body: (
+      <div className="flex flex-col gap-2">
+        <p>
+          The timeline above the log table renders log volume per bucket over the active window. Drag across it to
+          select a fixed time range — it narrows the log table, metrics, and dashboards below to that window; click
+          "Clear selection" to go back to the default (rolling "all time") view.
+        </p>
+      </div>
+    ),
+  },
+  {
+    id: 'log-preview',
+    title: 'Log preview',
+    body: (
+      <div className="flex flex-col gap-2">
+        <p>
+          The log table lists ingested lines newest-last, each with its sequence number, timestamp, and raw text. The
+          column picker (top-right) adds a column per declared param, showing that line's derived value for it (or a
+          blank if it didn't match) — a quick way to eyeball params without switching to the Metrics panel.
+        </p>
+      </div>
+    ),
+  },
   {
     id: 'metrics',
     title: 'Metrics',
@@ -200,17 +227,75 @@ const SECTIONS: DocSection[] = [
       </div>
     ),
   },
+  {
+    id: 'settings',
+    title: 'Settings',
+    body: (
+      <div className="flex flex-col gap-2">
+        <p>
+          The Settings panel controls process-wide state: colour scheme, the maximum number of logs kept in memory
+          (blank means unlimited), and imported/linked CSS. These apply immediately and persist to the single
+          settings file on disk — no save button needed.
+        </p>
+      </div>
+    ),
+  },
+  {
+    id: 'presets',
+    title: 'Presets',
+    body: (
+      <div className="flex flex-col gap-2">
+        <p>
+          The Presets panel manages profiles: create, switch, and delete them. Switching activates a profile's
+          params/metrics in the running engine immediately, with no restart needed — see the <em>General idea</em>{' '}
+          section above for what a profile stores.
+        </p>
+      </div>
+    ),
+  },
 ]
 
-export function DocsPanel() {
+/** How long a flashed section stays highlighted before settling back to normal. */
+const FLASH_DURATION_MS = 1200
+
+export function DocsPanel({ target }: { target?: DocsTarget | null }) {
   const [openId, setOpenId] = useState<string | null>(SECTIONS[0].id)
+  const [flashId, setFlashId] = useState<string | null>(null)
+  const sectionRefs = useRef<Record<string, HTMLDivElement | null>>({})
+
+  // Keyed on `target?.nonce` (not `target?.sectionId`) so clicking the same
+  // "?" icon twice in a row re-triggers the flash rather than being a no-op
+  // because the panel is already open to that section.
+  useEffect(() => {
+    if (!target) return
+    setOpenId(target.sectionId)
+    const raf = requestAnimationFrame(() => {
+      sectionRefs.current[target.sectionId]?.scrollIntoView({ behavior: 'smooth', block: 'nearest' })
+    })
+    setFlashId(target.sectionId)
+    const timeout = setTimeout(() => setFlashId(null), FLASH_DURATION_MS)
+    return () => {
+      cancelAnimationFrame(raf)
+      clearTimeout(timeout)
+    }
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [target?.nonce])
 
   return (
     <div className="flex flex-col gap-1 text-sm text-text-secondary">
       {SECTIONS.map((section) => {
         const isOpen = openId === section.id
+        const isFlashing = flashId === section.id
         return (
-          <div key={section.id} className="rounded border border-border">
+          <div
+            key={section.id}
+            ref={(el) => {
+              sectionRefs.current[section.id] = el
+            }}
+            className={`rounded border transition-colors duration-500 ${
+              isFlashing ? 'border-accent bg-accent-soft/25' : 'border-border'
+            }`}
+          >
             <button
               type="button"
               onClick={() => setOpenId(isOpen ? null : section.id)}

webapp/src/components/FilterBar.tsx

@@ -1,4 +1,5 @@
 import { useState } from 'react'
+import { HelpIcon } from './HelpIcon'
 
 /**
  * Input for the syntax-aware pest-parsed filter language described in the
@@ -27,6 +28,7 @@ export function FilterBar({
       }}
     >
       <div className="flex items-center gap-2">
+        <HelpIcon sectionId="filtering" label="Help: Filtering" />
         <input
           className="flex-1 rounded border border-border-soft bg-surface-1 px-2 py-1 text-sm text-text placeholder:text-text-subtle focus:border-border-strong focus:outline-none"
           placeholder='regex("error") and sequence<5 or timestamp>12:00'

webapp/src/components/HelpIcon.tsx

@@ -0,0 +1,21 @@
+import { useDocsNav } from '../lib/docsNav'
+
+/**
+ * A small "?" affordance that opens the Docs panel scrolled to (and
+ * flashing) a specific section (ticket 021), instead of the user having to
+ * find it themselves in the Docs accordion.
+ */
+export function HelpIcon({ sectionId, label }: { sectionId: string; label?: string }) {
+  const { openSection } = useDocsNav()
+  return (
+    <button
+      type="button"
+      onClick={() => openSection(sectionId)}
+      title="Open docs"
+      aria-label={label ?? 'Open docs for this section'}
+      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"
+    >
+      ?
+    </button>
+  )
+}

webapp/src/components/LogPreview.tsx

@@ -4,6 +4,7 @@ import {
   metricPrimitiveToDisplayString,
   type LogEntry,
 } from '../lib/api'
+import { HelpIcon } from './HelpIcon'
 
 /// localStorage key for LogPreview's selected param columns. Namespaced
 /// under `ottyl.` since this is the app's first localStorage usage — kept
@@ -126,7 +127,8 @@ export function LogPreview({ logs }: { logs: LogEntry[] }) {
 
   return (
     <div className="flex flex-1 flex-col overflow-hidden">
-      <div className="flex justify-end border-b border-border-faint px-3 py-1">
+      <div className="flex items-center justify-between border-b border-border-faint px-3 py-1">
+        <HelpIcon sectionId="log-preview" label="Help: Log preview" />
         <ColumnPicker paramNames={paramNames} visible={visible} onToggle={toggleColumn} />
       </div>
       <div className="flex-1 overflow-auto">

webapp/src/components/LogTimeline.tsx

@@ -1,5 +1,6 @@
 import { useRef, useState } from 'react'
 import type { TimelineBucket } from '../lib/api'
+import { HelpIcon } from './HelpIcon'
 
 export interface TimeRange {
   startMs: number
@@ -59,7 +60,10 @@ export function LogTimeline({
   return (
     <div className="border-b border-border p-3">
       <div className="mb-1 flex items-center justify-between text-xs text-text-subtle">
-        <span>Timeline</span>
+        <span className="flex items-center gap-1.5">
+          Timeline
+          <HelpIcon sectionId="timeline" label="Help: Timeline" />
+        </span>
         {range && (
           <button className="underline hover:text-text-secondary" onClick={() => onSelectRange(null)}>
             Clear selection

webapp/src/components/Metrics.tsx

@@ -10,6 +10,7 @@ import {
   type MetricDeclaration,
   type MetricParamMatcher,
 } from '../lib/api'
+import { HelpIcon } from './HelpIcon'
 
 const EMPTY_MATCHER: MetricParamMatcher = { param_name: '', capture_group: '', kind: 'string' }
 
@@ -156,7 +157,10 @@ export function Metrics({ range }: { range: TimeRange | null }) {
 
   return (
     <div className="border-b border-border p-3 text-sm">
-      <div className="mb-2 text-xs text-text-subtle">Metrics</div>
+      <div className="mb-2 flex items-center gap-1.5 text-xs text-text-subtle">
+        Metrics
+        <HelpIcon sectionId="metrics" label="Help: Metrics" />
+      </div>
       <div className="flex gap-4">
         <form onSubmit={handleSubmit} className="w-80 shrink-0 space-y-2">
           <div>

webapp/src/components/NavMenu.tsx

@@ -2,7 +2,9 @@ import { useEffect, useState } from 'react'
 import type { Stats } from '../lib/api'
 import type { ColorScheme } from '../lib/api'
 import { useSettingsPanel } from '../lib/useSettingsPanel'
+import { useDocsNav, type DocsTarget } from '../lib/docsNav'
 import { DocsPanel } from './Docs'
+import { HelpIcon } from './HelpIcon'
 
 type PanelName = 'settings' | 'presets' | 'docs' | null
 
@@ -31,11 +33,30 @@ const COLOR_SCHEMES: ColorScheme[] = [
 export function NavMenu({ stats }: { stats: Stats | null }) {
   const [openPanel, setOpenPanel] = useState<PanelName>(null)
   const panel = useSettingsPanel()
+  const docsNav = useDocsNav()
+  const [docsPanelTarget, setDocsPanelTarget] = useState<DocsTarget | null>(null)
 
   function togglePanel(name: PanelName) {
     setOpenPanel((current) => (current === name ? null : name))
   }
 
+  // A "?" icon (ticket 021) always opens Docs to that section and flashes it,
+  // even if Docs is already open to a different section — hence forcing
+  // `openPanel` here rather than toggling.
+  useEffect(() => {
+    if (!docsNav.target) return
+    setOpenPanel('docs')
+    setDocsPanelTarget(docsNav.target)
+  }, [docsNav.target])
+
+  // Opening Docs the normal way (this button, not a "?" icon) behaves as
+  // before: no forced section, no flash — so any pending help-triggered
+  // target is cleared.
+  function handleDocsButtonClick() {
+    togglePanel('docs')
+    setDocsPanelTarget(null)
+  }
+
   return (
     <div className="flex h-full">
       <div className="flex h-full w-48 shrink-0 flex-col justify-between border-r border-border p-3">
@@ -63,7 +84,7 @@ export function NavMenu({ stats }: { stats: Stats | null }) {
             </button>
             <button
               type="button"
-              onClick={() => togglePanel('docs')}
+              onClick={handleDocsButtonClick}
               className={`rounded px-2 py-1 text-left hover:bg-surface-2 ${
                 openPanel === 'docs' ? 'bg-surface-2 text-text' : ''
               }`}
@@ -93,7 +114,11 @@ export function NavMenu({ stats }: { stats: Stats | null }) {
           }`}
         >
           <div className="mb-3 flex items-center justify-between">
+            <div className="flex items-center gap-1.5">
               <h2 className="text-sm font-semibold text-text">{PANEL_TITLES[openPanel]}</h2>
+              {openPanel === 'settings' && <HelpIcon sectionId="settings" label="Help: Settings" />}
+              {openPanel === 'presets' && <HelpIcon sectionId="presets" label="Help: Presets" />}
+            </div>
             <button
               type="button"
               onClick={() => setOpenPanel(null)}
@@ -110,7 +135,7 @@ export function NavMenu({ stats }: { stats: Stats | null }) {
           )}
           {openPanel === 'settings' && <SettingsPanel panel={panel} />}
           {openPanel === 'presets' && <PresetsPanel panel={panel} />}
-          {openPanel === 'docs' && <DocsPanel />}
+          {openPanel === 'docs' && <DocsPanel target={docsPanelTarget} />}
         </div>
       )}
     </div>

webapp/src/lib/docsNav.tsx

@@ -0,0 +1,35 @@
+import { createContext, useCallback, useContext, useMemo, useRef, useState, type ReactNode } from 'react'
+
+/** One request to open the Docs panel scrolled to a specific section (ticket 021). */
+export interface DocsTarget {
+  sectionId: string
+  /** Bumped on every request, even to the same section, so a repeat click re-triggers the flash. */
+  nonce: number
+}
+
+interface DocsNavValue {
+  target: DocsTarget | null
+  openSection: (sectionId: string) => void
+}
+
+const DocsNavContext = createContext<DocsNavValue | null>(null)
+
+/** Wraps the app so any component can open Docs to a specific section via `useDocsNav`. */
+export function DocsNavProvider({ children }: { children: ReactNode }) {
+  const [target, setTarget] = useState<DocsTarget | null>(null)
+  const nonceRef = useRef(0)
+
+  const openSection = useCallback((sectionId: string) => {
+    nonceRef.current += 1
+    setTarget({ sectionId, nonce: nonceRef.current })
+  }, [])
+
+  const value = useMemo(() => ({ target, openSection }), [target, openSection])
+  return <DocsNavContext.Provider value={value}>{children}</DocsNavContext.Provider>
+}
+
+export function useDocsNav(): DocsNavValue {
+  const ctx = useContext(DocsNavContext)
+  if (!ctx) throw new Error('useDocsNav must be used within a DocsNavProvider')
+  return ctx
+}