fix(landing): fill the Codex Plugin mega-menu column and adopt the dsh one-line installer (#7139)

* fix(landing): fill the Codex Plugin mega-menu column and adopt the dsh one-line installer

The product mega menu's Codex Plugin column rendered as a blank panel
next to the populated Solution and Agent columns because it carried a
head link only. Fill it with the plugin ecosystem's real destinations:
the install anchor (reusing the plugin page's translated phase label,
no new i18n keys) plus the Codex Design and DeepSeek Harness
collection pages.

The DeepSeek Harness agent guide still taught the manual
npm-install path that requires a preinstalled Node.js toolchain. The
published installer flow replaces it: per-OS one-line commands from
open-design.ai/install-dsh.*, an isolated user-directory toolchain
with no sudo and no global Node.js changes, pinned to the release
OpenDesign has verified, finishing in dsh web for API-key setup.
Setup section, credential note, quick-summary steps, and FAQ updated
in both the English and Chinese guides; installer-specific FAQ
entries added.

* fix(landing): shape the Feature column per design and promote DeepSeek Harness

Rework the first mega-panel column to the reviewed design: a localized
Feature category head (new header i18n key across all 18 locales) with
Codex Plugin as its entry, replacing the interim link list. In the
Agent column, move DeepSeek Harness to the top with a red new-dot to
mark the freshly launched integration.

* fix(landing): roll the one-line installer into every active locale of the Harness guide

The landing test suite guards the DeepSeek Harness guide content per
active locale, so the installer switch has to land everywhere at once:
ja/ko/de/fr/es/ru/pt-br/it/tr setup sections now carry the three
per-OS one-line commands, the installer behavior list, the updated
Web UI step and credential note, plus the reworked install FAQ and two
new installer FAQs (translated, not machine-padded). Retired locales
(vi/pl/id/nl/ar/uk/zh-tw) keep their legacy dead copy untouched.

The content guard flips accordingly: it now requires all three
installer URLs and rejects any resurfacing of the manual
npm-install path; EN/ZH phrase anchors track the new intro copy.

147/147 landing tests pass; astro check clean.

* fix(landing): refocus the Harness guide on design and add HowTo schema

The guide led with a 'does DeepSeek Harness have a GUI' angle that is
off the page's actual message. Refocus every active locale on the real
narrative — designing with DeepSeek Harness through OpenDesign:
design-first title and description, the GUI section, its TOC entry and
FAQ removed (en/zh plus the nine localized copies; retired locales
keep their dead copy).

SEO on top of the accurate tutorial: add HowTo structured data built
from the real five-step walkthrough (install → download → detect →
connect → first task) with per-step section anchors, joining the
existing Breadcrumb/WebPage/ItemList/FAQPage blocks. The content
guard's title anchor tracks the new intent.

* fix(landing): keep a #gui compatibility anchor on the Harness setup section

The GUI section was removed in the design-first refocus, which broke
saved and search-indexed /agents/deepseek-harness-design/#gui deep
links. Alias the anchor onto the setup section so those links keep
landing on content, without reintroducing the GUI copy.

* fix(landing): give each HowToStep its instructional text

The HowTo steps carried only headings and anchors; schema consumers
that require an instructional field saw five names with no directions.
Each step now carries its section's lead paragraph as plain text
(markdown links and code markers stripped), falling back to the
heading when a section opens without a paragraph.

---------

Co-authored-by: Joey <236967869+joeylee12629-star@users.noreply.github.com>

Author: joeylee12629-star

apps/landing-page/app/_components/header.tsx

@@ -73,7 +73,10 @@ const TOOL_ENTRIES: ReadonlyArray<{ href: string; key: SolutionPageKey }> = [
 
 // Agent column — the coding agents with a dedicated long-form design page
 // upstream. Routes stay in lockstep with main's /agents/ hub.
-const AGENTS: ReadonlyArray<{ name: string; route: string }> = [
+const AGENTS: ReadonlyArray<{ name: string; route: string; highlight?: boolean }> = [
+  // DeepSeek Harness leads with a red-dot highlight while its integration is
+  // the freshly launched entry (2026-08 request); demote when the push ends.
+  { name: 'DeepSeek Harness', route: 'deepseek-harness-design', highlight: true },
   { name: 'Codex', route: 'codex-design' },
   { name: 'Cursor Agent', route: 'cursor-design' },
   { name: 'Claude Code', route: 'claude-code-design' },
@@ -84,7 +87,6 @@ const AGENTS: ReadonlyArray<{ name: string; route: string }> = [
   { name: 'Grok Build', route: 'grok-design' },
   { name: 'Kimi CLI', route: 'kimi-design' },
   { name: 'DeepSeek TUI', route: 'deepseek-design' },
-  { name: 'DeepSeek Harness', route: 'deepseek-harness-design' },
   { name: 'Trae CLI', route: 'trae-cli-design' },
   { name: 'Aider', route: 'aider-design' },
   { name: 'Antigravity', route: 'antigravity-design' },
@@ -245,25 +247,29 @@ export function Header({
                 className='nav-dropdown nav-dropdown-mega'
                 aria-label={productMenuCopy.product}
               >
-                {/* Plugin column — the Codex plugin entry. The product
-                    family (HTML Anything / HTML Video / Codex Slides) moved
-                    to the footer only (2026-08 nav consolidation); the mega
-                    panel now carries Plugin + the former Solution groups. */}
+                {/* Feature column — the first mega-panel group. The former
+                    head-only "Codex Plugin" column read as a blank panel next
+                    to the populated Solution/Agent columns (live bug), so the
+                    column is now the localized "Feature" category with Codex
+                    Plugin as its first entry (2026-08 design). The product
+                    family (HTML Anything / HTML Video / Codex Slides) stays
+                    footer-only per the 2026-08 nav consolidation. */}
                 <li className='nav-mega-col nav-mega-col-merged'>
-                  {/* Product name as the column head-link, not a translatable
-                      phrase — same convention as "Codex Slides" before it.
-                      The localized "Plugins" label is reserved for the
-                      Resources → /plugins/ catalog hub to avoid one chrome
-                      word pointing at two destinations. */}
-                  <a
-                    href={href('/codex-plugin/')}
-                    className={
-                      'nav-mega-col-head' +
-                      (active === 'open-design-plugin' ? ' is-active' : '')
-                    }
-                  >
-                    Codex Plugin
-                  </a>
+                  <span className='nav-mega-col-head'>{productMenuCopy.feature}</span>
+                  <ul className='nav-mega-list'>
+                    {/* Product name, not a translatable phrase — same
+                        convention as the Agent column entries. */}
+                    <li>
+                      <a
+                        href={href('/codex-plugin/')}
+                        className={
+                          active === 'open-design-plugin' ? 'is-active' : undefined
+                        }
+                      >
+                        <span className='dropdown-name'>Codex Plugin</span>
+                      </a>
+                    </li>
+                  </ul>
                 </li>
                 {/* Former Solution dropdown, folded into the mega panel as
                     three side-by-side columns (Use cases / Roles / Tools). */}
@@ -330,7 +336,12 @@ export function Header({
                     {AGENTS.map((agent) => (
                       <li key={agent.route}>
                         <a href={href(`/agents/${agent.route}/`)}>
-                          <span className='dropdown-name'>{agent.name}</span>
+                          <span className='dropdown-name'>
+                            {agent.name}
+                            {agent.highlight ? (
+                              <span className='nav-new-dot' aria-hidden='true'></span>
+                            ) : null}
+                          </span>
                         </a>
                       </li>
                     ))}