The partner-embed check becomes something a person can open

Under the Playwright policy only rega runs a browser here, so this
check's result has to come from someone else's eyes. But the partner
page only ever existed INSIDE check-embedded-rtl — two createServer calls
on ephemeral ports — so "open a partner page at a foreign origin" was not
a thing anyone but the gate could do. NEEDS-EYES rows 3, 4 and 6 name a
runnable probe or an exact URL; row 7 was mine, and it named a construct
that lived in my own process.

--emit writes the same pages to disk, with the two-terminal recipe and
what to look at, so the item is reproducible by whoever has the browser.

⚠ THEY GO IN documentation/, NOT _qa-cycle/. I wrote them there first and
then checked: _qa-cycle is gitignored (.gitignore:113), so the files
could never have travelled to the person who needs them — which is the
entire point. documentation/ is tracked and already carries
README-embed-example.md.

⚠ AND THE ?lang=ar FIXTURE CARRIES NO locale IN ITS profile-config —
1100 bytes against 1114. The two channels reach the document-direction
code by different routes and detectLocale() reads the URL FIRST, so a
config that also supplied the locale would let a reviewer believe the URL
had done it when it had not. The first emit produced all three files
BYTE-IDENTICAL, which would have handed someone three pages they could
not tell apart; I only caught it by checking the emitted sizes rather
than trusting that the flag had taken effect.

The CASES array now carries the ?lang= row itself, so this stands alone:
the emit produces every fixture committed beside it. It previously
depended on the library/ commit for that row, which left the repo with a
fixture the tool would not regenerate — worse than either half.

Also: --emit was being consumed as the baseUrl positional ("SKIP —
nothing served at --emit"). Flags are filtered out of it now. That is the
same bug, in the same shape, that check-leaf-english-leaks had three days
ago — worth knowing it recurs in any gate that takes both a positional
and flags.

documentation/needs-eyes/README.md

@@ -0,0 +1,60 @@
+# needs-eyes — partner-embed fixtures
+
+Under the Playwright policy (Driver, 2026-09-25) only **rega** runs a browser on the VPS, and the
+Driver's laptop is the other pair of eyes. So a check that can only be seen has to be *openable by
+someone else* — not a construct that lives inside one agent's gate process.
+
+These pages are generated, not hand-written:
+
+```
+node internal/check-embedded-rtl.mjs --emit
+```
+
+`check-embedded-rtl` builds its partner page on two ephemeral ports inside its own process. That is
+fine for a headless assertion and useless for a human: "open a partner page at a foreign origin"
+was not a thing anyone but the gate could do. `--emit` writes the same page to disk so the
+needs-eyes item is reproducible.
+
+## What each file is for
+
+| file | channel under test | open it as |
+|---|---|---|
+| `partner-poster-wall.html` | `profile-config.locale` — the channel a **host** sets | plain |
+| `partner-upg-100-mfe.html` | same, on the composite | plain |
+| `partner-poster-wall-lang-ar.html` | `?lang=` — the channel a **reader** follows | **with `?lang=ar`** |
+
+⚠ **The `?lang=ar` file deliberately carries no `locale` in its `profile-config`** (1100 bytes vs
+1114). The two channels reach the document-direction code by different routes, and
+`detectLocale()` reads the URL *first*. If the config also supplied the locale, a reader could
+believe the URL had done it when it had not — and the defect this fixture exists for only fires on
+the URL channel. An earlier version of the emit produced all three files byte-identical, which
+would have handed a reviewer three pages they could not tell apart.
+
+## How to use it
+
+Two terminals, and **the origins must differ** — same-origin hides the bug:
+
+```
+# 1) the tree, WITH CORS (a partner embed uses crossorigin="anonymous", so the
+#    browser demands Access-Control-Allow-Origin; `bun run serve` does not send it,
+#    a real CDN does)
+npx http-server public -p 47395 --cors -s
+
+# 2) these fixtures
+npx http-server documentation/needs-eyes -p 47393 -s
+
+# 3) open
+http://127.0.0.1:47393/partner-poster-wall-lang-ar.html?lang=ar
+```
+
+## What to look at
+
+The partner page's own heading — **"Partner page"** — must stay **left**-aligned and the
+document's `<html>` must carry no `dir`, while the plugin below it mirrors right-to-left.
+
+If the heading jumps to the right, the embedded plugin flipped its host's whole page and the check
+has **failed**. That was the real defect: an RTL locale was written to
+`document.documentElement.dir` whenever it resolved, so a reader following a `?lang=ar` link to a
+partner's site got the partner's headings, nav and footer flipped. The fix
+(`window.MAP_OWNS_PAGE`, packet/vertical 2a502dd8) is that only a page the generator wrote may
+have its direction set; absence of the flag means restraint.

documentation/needs-eyes/partner-poster-wall-lang-ar.html

@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html lang="en"><head><meta charset="utf-8"><title>partner</title>
+<style>html,body{margin:0}#w{height:900px}</style></head>
+<body><h1 id="partner-heading">Partner page</h1><div id="w"></div>
+<!-- A REAL PARTNER EMBED SETS THIS. The generated leaf pages bake window.MAP_APP_API_URL, and
+     without it every data fetch resolves same-origin against the partner and fails, so the wall
+     renders zero cards and the locale has nothing to translate. The first run of this gate
+     omitted it and reported "never mounted" — a harness gap, not the RTL defect. -->
+<script>window.MAP_APP_API_URL = "https://pray.doxa.life";</script>
+<script src="http://127.0.0.1:47395/dx-maps/my-upg-100-list/my-upg-100-list.js" crossorigin="anonymous"></script>
+<script>
+  var el = document.createElement("my-upg-100-list-map");
+  el.setAttribute('profile-config', JSON.stringify({ profile: "poster-wall",
+    assetsBase: "http://127.0.0.1:47395/dx-maps/assets" }));
+  el.style.cssText = 'display:block;width:100%;height:900px';
+  document.getElementById('w').appendChild(el);
+</script></body></html>

documentation/needs-eyes/partner-poster-wall.html

@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html lang="en"><head><meta charset="utf-8"><title>partner</title>
+<style>html,body{margin:0}#w{height:900px}</style></head>
+<body><h1 id="partner-heading">Partner page</h1><div id="w"></div>
+<!-- A REAL PARTNER EMBED SETS THIS. The generated leaf pages bake window.MAP_APP_API_URL, and
+     without it every data fetch resolves same-origin against the partner and fails, so the wall
+     renders zero cards and the locale has nothing to translate. The first run of this gate
+     omitted it and reported "never mounted" — a harness gap, not the RTL defect. -->
+<script>window.MAP_APP_API_URL = "https://pray.doxa.life";</script>
+<script src="http://127.0.0.1:47395/dx-maps/my-upg-100-list/my-upg-100-list.js" crossorigin="anonymous"></script>
+<script>
+  var el = document.createElement("my-upg-100-list-map");
+  el.setAttribute('profile-config', JSON.stringify({ profile: "poster-wall", locale: 'ar',
+    assetsBase: "http://127.0.0.1:47395/dx-maps/assets" }));
+  el.style.cssText = 'display:block;width:100%;height:900px';
+  document.getElementById('w').appendChild(el);
+</script></body></html>

documentation/needs-eyes/partner-upg-100-mfe.html

@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html lang="en"><head><meta charset="utf-8"><title>partner</title>
+<style>html,body{margin:0}#w{height:900px}</style></head>
+<body><h1 id="partner-heading">Partner page</h1><div id="w"></div>
+<!-- A REAL PARTNER EMBED SETS THIS. The generated leaf pages bake window.MAP_APP_API_URL, and
+     without it every data fetch resolves same-origin against the partner and fails, so the wall
+     renders zero cards and the locale has nothing to translate. The first run of this gate
+     omitted it and reported "never mounted" — a harness gap, not the RTL defect. -->
+<script>window.MAP_APP_API_URL = "https://pray.doxa.life";</script>
+<script src="http://127.0.0.1:47395/dx-maps/my-upg-100-list/my-upg-100-list.js" crossorigin="anonymous"></script>
+<script>
+  var el = document.createElement("my-upg-100-list-map");
+  el.setAttribute('profile-config', JSON.stringify({ profile: "upg-100-mfe", locale: 'ar',
+    assetsBase: "http://127.0.0.1:47395/dx-maps/assets" }));
+  el.style.cssText = 'display:block;width:100%;height:900px';
+  document.getElementById('w').appendChild(el);
+</script></body></html>

internal/check-embedded-rtl.mjs

@@ -28,8 +28,21 @@ import { servesThisTree } from './_serves-this-tree.mjs'
 import { TREE_NAME } from './_tree-name.mjs'
 
 const ROOT = resolve(dirname(fileURLToPath(import.meta.url)), '..')
-const BASE = process.argv[2] || process.env.BASE_URL || 'http://127.0.0.1:4173'
+// ⚠ FILTER FLAGS OUT OF THE POSITIONAL. `--emit` was consumed as the baseUrl and the gate
+// reported "SKIP — nothing served at --emit". Exactly the bug I hit on check-leaf-english-leaks
+// last week; the same shape, in a different file, three days apart.
+const BASE = process.argv.slice(2).find((a) => !a.startsWith('--'))
+  || process.env.BASE_URL || 'http://127.0.0.1:4173'
 const HOST_PORT = Number(process.env.RTL_HOST_PORT || 47393)
+// ★ --emit WRITES THE PARTNER PAGE TO DISK INSTEAD OF MEASURING IT.
+// Under the Playwright policy (Driver, 2026-09-25) only rega runs a browser, so this check's
+// result now has to be produced by someone else's eyes. But the partner page only ever existed
+// INSIDE this process — two createServer calls on ephemeral ports — so "open a partner page at a
+// foreign origin" was not a thing anyone could actually do. NEEDS-EYES rows 3, 4 and 6 name a
+// runnable probe or an exact URL; row 7 (mine) named a construct that lived in my own memory.
+// --emit closes that: it writes a self-contained page plus a two-line serve recipe, so the item
+// is reproducible by whoever has the browser.
+const EMIT = process.argv.includes('--emit')
 
 let reachable = false
 try { const r = await fetch(`${BASE}/${TREE_NAME}/manifest.json`, { signal: AbortSignal.timeout(4000) }); reachable = r.ok } catch { /* precondition */ }
@@ -38,12 +51,23 @@ const treeCheck = await servesThisTree(BASE, ROOT)
 if (!treeCheck.ok) { console.error(`EMBEDDED-RTL: NOT MEASURED — ${treeCheck.why}`); process.exit(2) }
 
 // A PARTNER PAGE on a foreign origin: its own <html dir> is LTR and must stay that way.
+// ⚠ BOTH CHANNELS. profile-config is how a HOST sets the language; ?lang= on the partner's OWN
+// url is how a READER does, and detectLocale() reads the URL FIRST. They reach the
+// document-direction code by different routes, so a check that drives only one proves nothing
+// about the other — which is why the URL case exists as a row here rather than as a variant of
+// the config one. The emit writes a fixture per row, so this array IS the needs-eyes inventory.
 const CASES = [
   { id: 'my-upg-100-list', tag: 'my-upg-100-list-map', profile: 'upg-100-mfe' },
   { id: 'my-upg-100-list', tag: 'my-upg-100-list-map', profile: 'poster-wall' },
+  { id: 'my-upg-100-list', tag: 'my-upg-100-list-map', profile: 'poster-wall', urlLang: 'ar' },
 ]
 const TREE_PORT = Number(process.env.RTL_TREE_PORT || 47395)
 const TREE = `http://127.0.0.1:${TREE_PORT}`
+// ⚠ THE URL CASE MUST NOT ALSO SET locale IN profile-config. The two channels reach the
+// document-dir code by different routes and the whole point of the ?lang= case is to exercise the
+// URL one alone. Emitting all three files byte-identical (measured: 1114 bytes each) would hand a
+// reader a page that cannot distinguish them — and would let the config channel supply the locale
+// while the reader believed the URL had.
 const hostHtml = (c) => `<!DOCTYPE html>
 <html lang="en"><head><meta charset="utf-8"><title>partner</title>
 <style>html,body{margin:0}#w{height:900px}</style></head>
@@ -56,7 +80,7 @@ const hostHtml = (c) => `<!DOCTYPE html>
 <script src="${TREE}/${TREE_NAME}/${c.id}/${c.id}.js" crossorigin="anonymous"><\/script>
 <script>
   var el = document.createElement(${JSON.stringify(c.tag)});
-  el.setAttribute('profile-config', JSON.stringify({ profile: ${JSON.stringify(c.profile)}, locale: 'ar',
+  el.setAttribute('profile-config', JSON.stringify({ profile: ${JSON.stringify(c.profile)}${c.urlLang ? '' : ", locale: 'ar'"},
     assetsBase: ${JSON.stringify(TREE + `/${TREE_NAME}/assets`)} }));
   el.style.cssText = 'display:block;width:100%;height:900px';
   document.getElementById('w').appendChild(el);
@@ -88,6 +112,33 @@ const srv = createServer((req, res) => {
 })
 await new Promise((r) => srv.listen(HOST_PORT, '127.0.0.1', r))
 
+if (EMIT) {
+  const { writeFileSync, mkdirSync } = await import('node:fs')
+  // ⚠ documentation/, NOT _qa-cycle/. _qa-cycle is GITIGNORED (.gitignore:113), so pages written
+  // there cannot travel to whoever has the browser — which is the entire point of emitting them.
+  // documentation/ is tracked and already carries README-embed-example.md, so a partner-embed
+  // fixture belongs beside it.
+  const outDir = resolve(ROOT, 'documentation/needs-eyes')
+  mkdirSync(outDir, { recursive: true })
+  for (let i = 0; i < CASES.length; i++) {
+    const c = CASES[i]
+    const name = `partner-${c.profile}${c.urlLang ? `-lang-${c.urlLang}` : ''}.html`
+    writeFileSync(resolve(outDir, name), hostHtml(c))
+    console.log(`  wrote documentation/needs-eyes/${name}`
+      + `${c.urlLang ? `   open it WITH ?lang=${c.urlLang}` : ''}`)
+  }
+  console.log('\n  HOW TO USE (two terminals, and the ORIGINS MUST DIFFER — same-origin hides the bug):')
+  console.log(`    1) serve the tree WITH CORS on ${TREE_PORT}:`)
+  console.log(`       npx http-server public -p ${TREE_PORT} --cors -s`)
+  console.log(`    2) serve this folder on ${HOST_PORT}:`)
+  console.log(`       npx http-server documentation/needs-eyes -p ${HOST_PORT} -s`)
+  console.log(`    3) open http://127.0.0.1:${HOST_PORT}/partner-poster-wall-lang-ar.html?lang=ar`)
+  console.log('\n  WHAT TO LOOK AT: the partner page\'s own heading, "Partner page", must stay')
+  console.log('  LEFT-aligned and its <html dir> unset — while the plugin below it mirrors RTL.')
+  console.log('  If the heading jumps to the right, the embed flipped its host and this FAILED.')
+  process.exit(0)
+}
+
 const browser = await chromium.launch({ args: ['--use-gl=swiftshader', '--enable-unsafe-swiftshader'] })
 const WALK = `(root)=>{const o=[];const rec=(r)=>{for(const e of r.querySelectorAll('*')){o.push(e);if(e.shadowRoot)rec(e.shadowRoot)}};rec(root);return o}`
 const rows = []