fix(web): align the plan summary's usable-content rule with the tool

planSummary treated whitespace-only content as nameable, so a rejected call
whose args survive verbatim rendered a blank active clause beside a live +N.
The tool's own rule is trimmed non-empty; the row now uses it.

Also hoists the duplicated DSH_SNAPSHOT refresh flag out of the two assembled
snapshot files into their shared assembled-boot scaffolding.

apps/web/tests/todo-row.snapshot.ts

@@ -14,10 +14,9 @@ import { mkdirSync, writeFileSync } from 'node:fs'
 import { dirname, join } from 'node:path'
 import { fireEvent, screen, waitFor, within } from '@testing-library/react'
 import { describe, expect, it } from 'vitest'
-import { hasClass, installAssembledBootEnv, mountAssembledApp } from './assembled-boot.ts'
+import { hasClass, installAssembledBootEnv, mountAssembledApp, REFRESHING_GOLDEN } from './assembled-boot.ts'
 
 const EXPECTED = join(process.cwd(), 'apps/web/tests/snapshots/todo-row/parallel-plan.expected.txt')
-const refreshing = process.env.DSH_SNAPSHOT === 'record' || process.env.DSH_SNAPSHOT === 'refresh'
 
 installAssembledBootEnv()
 
@@ -63,7 +62,7 @@ describe('assembled todo surfaces', () => {
     if (toggle.getAttribute('aria-expanded') === 'false') fireEvent.click(toggle)
 
     const shape = todoShape(row, panel)
-    if (refreshing) {
+    if (REFRESHING_GOLDEN) {
       mkdirSync(dirname(EXPECTED), { recursive: true })
       writeFileSync(EXPECTED, shape)
     }