Reclaim mobile chrome: drop the editor's top banner, un-cramp the assistant

Two mobile complaints, both in the editor/assistant context:

- The global top bar (brand + account) sat above the editor's own
  garden-name strip — a whole banner of pure chrome over a full-screen
  canvas. Hide it on mobile in the editor (the same rationale that hides
  the bottom nav there) and fold a leaf/back affordance into the garden
  strip so there's still a way out. Desktop keeps the header. The editor's
  height band shrinks 8rem → 4rem on mobile to hand that space to the
  canvas; desktop stays 8rem since the header is still there.

- The assistant (and journal/history) rendered inside the rail peek
  capped at max-h-[50vh]; after the tab bar, header and input, messages
  got ~200px. That cap is right for the inspector (read alongside the
  canvas) but not for a mode where reading/typing is the task. Panel
  modes now take a taller slice (78vh) via a `tall` prop; the inspector
  keeps the 50vh peek. Chat message spacing loosened gap-2 → gap-3.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01H3zbym8Doka2d7D48maSgZ

web/src/components/layout/AppShell.tsx

@@ -43,12 +43,23 @@ export function AppShell() {
   // max-w-5xl reading measure the other pages use (#107).
   const canvasRoute = inEditor || inPublicGarden
   const showBottomNav = !!user && !canvasRoute
+  // On a phone the editor is a full-screen canvas — the same reason the bottom
+  // bar hides there. The global top bar (brand + account) is then pure chrome
+  // above the garden, so hide it too and let the editor's own strip carry a back
+  // affordance; desktop keeps the header. Only the editor, not the public view,
+  // which has no strip of its own to fall back on.
+  const hideHeaderOnMobile = inEditor
 
   const visibleSections = sections.filter((s) => !s.adminOnly || user?.isAdmin)
 
   return (
     <div className="flex min-h-full flex-col">
-      <header className="sticky top-0 z-20 border-b border-border bg-surface/90 backdrop-blur">
+      <header
+        className={cn(
+          'sticky top-0 z-20 border-b border-border bg-surface/90 backdrop-blur',
+          hideHeaderOnMobile && 'hidden md:block',
+        )}
+      >
         {/* The bar matches the content width below: constrained on reading pages,
             edge-to-edge on the canvas routes so the brand aligns with the editor. */}
         <nav className={cn('flex items-center gap-4 px-4 py-3', canvasRoute ? '' : 'mx-auto max-w-5xl')}>

web/src/editor/ChatPanel.tsx

@@ -143,7 +143,7 @@ export function ChatPanel({ gardenId, canEdit }: { gardenId: number; canEdit: bo
         </p>
       )}
 
-      <div className="flex min-h-0 flex-1 flex-col gap-2 overflow-y-auto">
+      <div className="flex min-h-0 flex-1 flex-col gap-3 overflow-y-auto">
         {history.isPending && <p className="text-sm text-muted">Loading the conversation…</p>}
         {/* A failed load rendering as an empty thread would look like the
             conversation had been lost, which is a much worse thing to believe. */}

web/src/editor/EditorRail.tsx

@@ -18,10 +18,13 @@ import { cn } from '@/lib/cn'
  *     closes completely when nothing needs it.
  *
  * Layout differs by breakpoint. Desktop: a fixed 20rem column beside the canvas.
- * Phone: an in-flow PEEK (#101) — a ≤50vh panel the editor's flex column places
- * BETWEEN the canvas and the always-visible mode bar, so the canvas shrinks to
- * keep the garden visible above it and the mode bar reachable below, rather than
- * a bottom sheet that covered the whole garden.
+ * Phone: an in-flow PEEK (#101) — a capped-height panel the editor's flex column
+ * places BETWEEN the canvas and the always-visible mode bar, so the canvas
+ * shrinks to keep the garden visible above it and the mode bar reachable below,
+ * rather than a bottom sheet that covered the whole garden. `tall` raises that
+ * cap for panel modes (journal/history/assistant), where reading and typing are
+ * the task and a half-height peek felt cramped; the inspector keeps the shorter
+ * peek so the canvas it describes stays in view.
  */
 
 export interface RailTab {
@@ -38,11 +41,14 @@ export function EditorRail({
   activeId,
   onActivate,
   onClose,
+  tall = false,
 }: {
   tabs: RailTab[]
   activeId: string
   onActivate: (id: string) => void
   onClose: () => void
+  /** Raise the mobile peek's height cap (panel modes want the room). */
+  tall?: boolean
 }) {
   const active = tabs.find((t) => t.id === activeId) ?? tabs[0]
   if (!active) return null
@@ -54,8 +60,9 @@ export function EditorRail({
         // canvas and the always-visible mode bar (the editor's flex column places
         // it there), so the garden stays visible above it and the mode bar stays
         // reachable below. The canvas flexes to fill whatever's left. Desktop: a
-        // fixed-width column beside the canvas.
-        'flex max-h-[50vh] min-h-0 shrink-0 flex-col rounded-t-xl border-t border-border bg-surface shadow-lg',
+        // fixed-width column beside the canvas (the cap doesn't apply there).
+        'flex min-h-0 shrink-0 flex-col rounded-t-xl border-t border-border bg-surface shadow-lg',
+        tall ? 'max-h-[78vh]' : 'max-h-[50vh]',
         'md:static md:max-h-none md:w-80 md:rounded-xl md:border md:shadow-sm',
       )}
     >

web/src/pages/GardenEditorPage.tsx

@@ -1,5 +1,5 @@
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
-import { getRouteApi } from '@tanstack/react-router'
+import { Link, getRouteApi } from '@tanstack/react-router'
 import { Alert } from '@/components/ui/Alert'
 import { Button } from '@/components/ui/Button'
 import { GardenCanvas } from '@/editor/GardenCanvas'
@@ -544,8 +544,13 @@ export function GardenEditorPage() {
   // 100dvh, not 100vh: on mobile Safari/Chrome 100vh is the *largest* viewport
   // (URL bar hidden), so with the bar showing the editor overflowed and pushed
   // the canvas bottom + Fit button under the browser chrome (#85).
+  //
+  // The subtracted band differs by breakpoint because the chrome does. On mobile
+  // the global top bar is hidden here (AppShell), so only <main>'s padding is
+  // above us — 4rem reclaims the ~48px the header used to cost the canvas. On
+  // desktop the header is present, so keep the original 8rem.
   return (
-    <div className="flex h-[calc(100dvh-8rem)] flex-col gap-3 md:flex-row">
+    <div className="flex h-[calc(100dvh-4rem)] flex-col gap-3 md:h-[calc(100dvh-8rem)] md:flex-row">
       {/* Desktop-only control column. On mobile these move to the bottom mode bar
           + a slim top strip so the canvas — the point of the screen — isn't shoved
           into a corner by a stack of controls (#99). */}
@@ -597,8 +602,17 @@ export function GardenEditorPage() {
 
       <div className="relative flex min-h-0 flex-1 flex-col gap-2">
         {/* Mobile top strip: the garden identity / season / share that live in the
-            desktop left column. md:hidden. */}
+            desktop left column, plus the way out. The global header is hidden on
+            mobile here (AppShell), so this leaf is the only route back to the
+            gardens list — it can't be dropped. md:hidden. */}
         <div className="flex items-center gap-2 md:hidden">
+          <Link
+            to="/gardens"
+            aria-label="All gardens"
+            className="-ml-1 shrink-0 rounded-md px-1.5 py-1 text-lg leading-none text-accent-strong outline-none focus-visible:ring-2 focus-visible:ring-accent/40"
+          >
+            🌱
+          </Link>
           <h1 className="min-w-0 flex-1 truncate text-base font-semibold tracking-tight" title={garden.name}>
             {garden.name}
           </h1>
@@ -673,6 +687,11 @@ export function GardenEditorPage() {
           tabs={railTabs}
           activeId={railTab}
           onActivate={setRailTab}
+          // The inspector is read alongside the canvas, so it stays a half-height
+          // peek. Journal/History/Assistant are the task themselves — reading and
+          // typing want room — so they take a taller slice on mobile (the canvas
+          // above just needs to stay glanceable as the assistant edits it).
+          tall={railTab !== 'inspector'}
           onClose={() => {
             // Only the inspector is *about* the selection, so only closing it
             // deselects; dismissing a panel leaves the canvas as you had it. Any