Address Gadfly review on the journal UI

The prop names were backwards. `canEdit` meant "may delete" and `canWrite` meant
"may rewrite the text" — which is the opposite of how either word reads, on a
component where the distinction is the entire permission model. They are now
canDelete and canRewrite.

An open edit draft never re-synced with its entry, so a refetch after someone
else's edit left a stale draft and a Cancel that restored the wrong text. It now
resyncs when the entry changes underneath, but only while not editing, so a
background refetch can't clobber what's being typed — the version guard is what
catches a genuine collision.

A 409 from an edit had no handling, so the component kept its stale version and
every retry conflicted again: a button that just doesn't work. A conflict now
invalidates, so the fresh version arrives.

Saving an empty edit returned silently, which also reads as a broken button. It
says why nothing happened, and points at Delete if that's what was meant. A
failed delete's error now clears on retry rather than making a second attempt
look like a second failure.

formatObservedAt let out-of-range parts roll over — 2026-13-45 rendering as
February 2027, confidently wrong. It shows the raw string instead.

Also: the scope select guards against a non-numeric value becoming a NaN
objectId and a cryptic 400; the journal total is memoized rather than
spread-and-reduced every render; EditorRail's doc comment no longer calls the
journal "later" now that it's here; and a static class list stopped being split
across two cn() arguments for no reason.

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

web/src/lib/journal.ts

@@ -6,7 +6,7 @@
 
 import { useInfiniteQuery, useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
 import { z } from 'zod'
-import { api } from './api'
+import { ApiError, api } from './api'
 
 export const journalEntrySchema = z.object({
   id: z.number(),
@@ -108,6 +108,12 @@ export function useUpdateJournalEntry(gardenId: number) {
       return journalEntrySchema.parse(await api.patch(`/journal/${id}`, rest))
     },
     onSuccess: () => invalidateJournal(qc, gardenId),
+    onError: (err) => {
+      // A 409 means the row moved on. Refetch so the component receives the
+      // current version — otherwise a retry resends the stale one and conflicts
+      // forever, which reads as a button that simply doesn't work.
+      if (err instanceof ApiError && err.isConflict) invalidateJournal(qc, gardenId)
+    },
   })
 }
 
@@ -133,6 +139,8 @@ export function today(): string {
  *  through a Date (which would shift it by the timezone offset). */
 export function formatObservedAt(iso: string): string {
   const [y, m, d] = iso.split('-').map(Number)
-  if (!y || !m || !d) return iso
+  // Out-of-range parts would silently roll over — 2026-13-45 becoming February
+  // 2027 — so show the raw string instead of a confidently wrong date.
+  if (!y || !m || !d || m < 1 || m > 12 || d < 1 || d > 31) return iso
   return new Date(y, m - 1, d).toLocaleDateString(undefined, { month: 'short', day: 'numeric', year: 'numeric' })
 }