Fix homepage Tablet layout: Hero grid, Tools icon, About columns, Newsletter/Footer stacking

- Hero.tsx: structural breakpoint reverted from lg: back to md: — the
  smaller CTA/subtitle/icon sizes added during the Mobile pass fit
  comfortably in the ~283px Tablet column, so the original 3-line-wrap
  problem that justified lg: doesn't recur. Tablet gets the real 5/7
  grid (image beside text) again instead of a stacked mobile layout.
- Tools.tsx: full-size (56px) card icon pushed from md: to lg: — at
  Tablet it dwarfed the still-close-to-floor title/description text.
- About.tsx: text/photo flex ratio swapped at Tablet (text gets the
  bigger share, no overlap) vs. the original ratio + overlap trick from
  lg: up, where it was designed for — Tablet's text column was too
  narrow for its fixed-width statement + quote/bio row otherwise.
- Newsletter.tsx/Footer.tsx: the input+button row and the logo/handle/
  legal-links row both went side-by-side at md:, but their surrounding
  columns didn't leave enough width at 768px — pushed to lg:flex-row.

app/components/Newsletter.tsx

@@ -98,8 +98,14 @@ export function Newsletter({
             ) : (
               <form onSubmit={handleSubmit} className="flex flex-1 flex-col gap-4 min-w-0 w-full">
 
-                {/* Input + submit button — stacked below md, side by side from md+ */}
-                <div className="flex flex-col md:flex-row gap-4 items-stretch w-full">
+                {/* Input + submit button — stacked below lg: (was md:).
+                    The card above already goes side-by-side at md: with a
+                    fixed-width copy column (--newsletter-copy-width), which
+                    only leaves ~200px for this form column at 768px — not
+                    enough room for input+button side by side. Stacked
+                    through the whole Tablet range instead, side by side
+                    again once the form column has real room at lg:. */}
+                <div className="flex flex-col lg:flex-row gap-4 items-stretch w-full">
                   <input
                     ref={emailRef}
                     type="email"