docs(email): document IMPORT structure + literal-hex brand constraint

docs/superpowers/plans/2026-06-26-email-templates-brand-hygiene.md

@@ -630,11 +630,11 @@ git commit -m "feat(email): convert digest.html to shared partials + brand, loop
 **Files:**
 - Modify: `email/README.md`
 
-- [ ] **Step 1: Fix the Partials section** — it currently says the partials are "included by the templates above" (was false, now true). State that every non-partial template `IMPORT`s `header.html` first and `footer.html` last, using the form confirmed in Task 3 (`emails/partials/header.html` or `.tpl`), and that `notification.html` imports `post-queue-body.html` for post-queue items.
+- [x] **Step 1: Fix the Partials section** — it currently says the partials are "included by the templates above" (was false, now true). State that every non-partial template `IMPORT`s `header.html` first and `footer.html` last, using the form confirmed in Task 3 (`emails/partials/header.html`), and document `post-queue-body.html` as the queued-post notification body fragment without claiming the current `notification.html` imports it.
 
-- [ ] **Step 2: Add a brand/constraint note to Editing notes** — add a bullet: brand colors are **literal inline hex** (Outlook/Gmail strip `var()`); `scss/westgate/_tokens.scss` holds the source values but cannot be referenced at runtime. Note the dark letterhead band + light cream card pattern, and that preheader copy lives in `languages/en-GB/email.json`.
+- [x] **Step 2: Add a brand/constraint note to Editing notes** — add a bullet: brand colors are **literal inline hex** (Outlook/Gmail strip `var()`); `scss/westgate/_tokens.scss` holds the source values but cannot be referenced at runtime. Note the dark letterhead band + light cream card pattern, and that preheader copy lives in `languages/en-GB/email.json`.
 
-- [ ] **Step 3: Commit**
+- [x] **Step 3: Commit**
 
 ```bash
 git add email/README.md

email/README.md

@@ -46,18 +46,24 @@ them to users on various events (password reset, digest, ban, etc.).
 
 ## Partials
 
-`partials/` holds fragments included by the templates above:
+`partials/` holds fragments imported by the templates above. Every
+non-partial template starts with `<!-- IMPORT emails/partials/header.html -->`
+and ends with `<!-- IMPORT emails/partials/footer.html -->`.
 
 - `header.html` — shared email head/header markup.
 - `footer.html` — shared footer with the unsubscribe block
   (`{{{ if showUnsubscribe }}}`).
-- `post-queue-body.html` — renders a queued post (category, topic, author,
+- `post-queue-body.html` — queued-post notification body fragment (category,
-  content) inside `notification.html` for post-queue notifications.
+  topic, author, content), maintained for use by a notification branch/template.
 
 ## Editing notes
 
 - These are emails: inline CSS, table layout, MSO/Outlook conditional
   comments. Keep that structure — don't refactor into modern CSS.
+- Brand colors are literal inline hex because Outlook/Gmail strip `var()`.
+  `scss/westgate/_tokens.scss` holds the source values but is not available at
+  runtime; keep the dark letterhead band + light cream card pattern. Preheader
+  copy lives in `languages/en-GB/email.json`.
 - Don't hardcode user-facing copy; add/replace `[[email:…]]` keys and define
   them in the language files.
 - Run `node scripts/check-emails.js` after converting templates. It enforces