refactor(scripts): consolidate gate scripts on mdast fences, parseArgs, and globSync

Implements the gate-consolidation Agent Note from the NIH dependency audit:

- Shared markdownFences helper in scripts/markdown.ts (mdast code-node visit);
  doc-typecheck and verify-type-equiv extract fences through it; md-fences.ts
  and the duplicated extractEquivBlocks regex scanner are deleted;
  markdownProseLines derives fenced lines from parsed code-node positions
  instead of a second fence regex.
- publint-all.ts and verify-built-package-invariants.mjs parse argv with
  node:util parseArgs instead of hand-stepped parseOptions copies.
- Five straggler readdirSync walks become globSync: verify-runtime-closure,
  dev-web discoverPluginDirs, verify-package-paths realPackageNames,
  verify-client-domain-graph listSources, publint-all addPath. The
  dirent-diagnostic walks in check-workspace-constraints.ts and clean.ts stay.

Behavior parity verified: pnpm run doc-sync and every rewritten gate produce
byte-identical output before and after on this tree.

Moves the owning Agent Note proposed -> implemented and re-records its pair.

scripts/publint-all.ts

@@ -3,18 +3,21 @@
 import {
   globSync,
   readFileSync,
-  readdirSync,
   statSync,
 } from 'node:fs'
 import { availableParallelism } from 'node:os'
 import { dirname, relative, resolve, sep } from 'node:path'
+import { parseArgs } from 'node:util'
 import { publint, type Message, type PackFile } from 'publint'
 import { formatMessage } from 'publint/utils'
 
 const CONCURRENCY_ENV = 'DSH_PUBLINT_CONCURRENCY'
 const repositoryRoot = resolve(import.meta.dirname, '..')
-const options = parseOptions(process.argv.slice(2))
-const packagesRoot = resolve(options.get('--packages-root') ?? repositoryRoot)
+const { values: options } = parseArgs({
+  args: process.argv.slice(2),
+  options: { 'packages-root': { type: 'string' } },
+})
+const packagesRoot = resolve(options['packages-root'] ?? repositoryRoot)
 
 interface PackageTarget {
   path: string
@@ -88,7 +91,9 @@ function publicationFiles(target: PackageTarget): PackFile[] {
 function addPath(path: string, paths: Set<string>): void {
   const stat = statSync(path)
   if (stat.isDirectory()) {
-    for (const entry of readdirSync(path)) addPath(resolve(path, entry), paths)
+    for (const entry of globSync('**/*', { cwd: path, withFileTypes: true })) {
+      if (entry.isFile()) paths.add(resolve(entry.parentPath, entry.name))
+    }
   } else if (stat.isFile()) {
     paths.add(path)
   }
@@ -144,20 +149,6 @@ function printResult(result: PublintResult): void {
   if (result.status === 'passed' && result.messages.length === 0) console.log('All good!')
 }
 
-function parseOptions(args: string[]): Map<string, string> {
-  const parsed = new Map<string, string>()
-  for (let index = 0; index < args.length; index += 2) {
-    const name = args[index]
-    const value = args[index + 1]
-    if (name !== '--packages-root' || value === undefined || value.startsWith('--')) {
-      throw new Error(`publint-all: expected [--packages-root PATH], got ${JSON.stringify(args)}.`)
-    }
-    if (parsed.has(name)) throw new Error(`publint-all: duplicate option ${name}.`)
-    parsed.set(name, value)
-  }
-  return parsed
-}
-
 const packages = workspacePackages()
 const concurrency = publintConcurrency(packages.length)
 console.log(`publint-all: linting ${packages.length} package(s) with ${concurrency} worker(s).`)