fix(site): grouped responsive nav, whitespace bugs, fabricated NGA claim

Header: 19 flat links collapse into 6 grouped items (Demo, Tools, Maps,
Models, Developers, Project) with accessible dropdowns (aria-expanded,
Esc, outside-click, hover-pin); under 1024px a hamburger opens a grouped
drawer with scroll lock, scrim and Esc close. Adds skip-to-content link.

Fix the Astro whitespace collapse where a space between text and an
inline link is dropped when they sit on different source lines; 16 sites
across 10 pages rendered "theU.S.", "issuewith", "monorepotracks",
"880fields", etc.

Remove the hallucinated NGA funding claim ("cooperative agreement
NSG-2021-XXX", never present on v1) from the footer, homepage CTA,
about page, and OpenAPI description. The about page now carries v1's
real supporters list (BGN, OGC, CalConnect, UNGEGN WGRS, ICAO,
Prof. Lyubomir Ivanov); footer keeps only the verifiable
"Ribose Inc. - BSD-2-Clause" line.

Also: single /ml footer link, security policy now points at the repo's
SECURITY.md, dropped a stray CSS brace, replaced the unavailable
DedicatedWorkerGlobalScope cast with a local WorkerContext type, and
scoped the hero e2e assertion (dev toolbar injects extra h1s).

Author: ronaldtse

e2e/home.spec.ts

@@ -10,7 +10,8 @@ test.describe("home page", () => {
   test("loads and renders hero", async ({ page }) => {
     await page.goto("/")
     await expect(page).toHaveTitle(/Interscript/i)
-    await expect(page.locator("h1")).toContainText(/Every/i)
+    // Scoped to the hero h1 — the Astro dev toolbar injects its own h1s.
+    await expect(page.locator("h1.hero-headline")).toContainText(/Every/i)
   })
 
   test("hero stats render real numbers", async ({ page }) => {