improvement(landing): rewrite hero subheading for target keywords

Replace the single-line hero description with the SEO/GEO-oriented
two-paragraph copy: lead by naming Sim as an AI agent and workflow
builder (pulling the brand into the first 150 visible chars), then
the integrations/LLM + deploy/monitor workspace framing.

Widen LandingHeroHeader's description prop from string to
string | string[]; a string still renders the exact same single <p>
(other marketing/solutions heroes unchanged), an array renders
stacked paragraphs within the same 58ch measure.

Author: mzxchandra

apps/sim/app/(landing)/components/hero/components/hero-header/hero-header.tsx

@@ -5,7 +5,8 @@ import { HeroCta } from '@/app/(landing)/components/hero-cta'
 import { LANDING_HERO_CTA_GAP } from '@/app/(landing)/components/landing-layout'
 
 interface LandingHeroHeaderProps {
-  description: string
+  /** A single paragraph, or an array of paragraphs rendered stacked within the same measure. */
+  description: string | string[]
   eyebrow?: ReactNode
   heading: ReactNode
   headingId: string
@@ -33,9 +34,22 @@ export function LandingHeroHeader({
           {heading}
         </h1>
 
-        <p className='w-full min-w-0 max-w-[58ch] text-pretty text-[var(--text-muted)] text-base leading-[1.5]'>
-          {description}
-        </p>
+        {Array.isArray(description) ? (
+          <div className='flex w-full min-w-0 max-w-[58ch] flex-col gap-3'>
+            {description.map((paragraph) => (
+              <p
+                key={paragraph}
+                className='text-pretty text-[var(--text-muted)] text-base leading-[1.5]'
+              >
+                {paragraph}
+              </p>
+            ))}
+          </div>
+        ) : (
+          <p className='w-full min-w-0 max-w-[58ch] text-pretty text-[var(--text-muted)] text-base leading-[1.5]'>
+            {description}
+          </p>
+        )}
 
         <div className={cn('max-sm:w-full', LANDING_HERO_CTA_GAP)}>
           <HeroCta />

apps/sim/app/(landing)/components/hero/hero.tsx

@@ -90,7 +90,10 @@ export function Hero() {
             and Managing AI Agents.
           </>
         }
-        description='Open source, with 1,000+ integrations and every major LLM. Build, deploy, and manage agents visually, conversationally, or with code.'
+        description={[
+          'Sim is an AI agent and workflow builder for teams creating agents that automate real work. Design workflows visually, describe what you need in natural language, or use code for complete control.',
+          'Connect your agents to 1,000+ integrations and every major LLM, then deploy, monitor, and improve them from one collaborative workspace.',
+        ]}
       />
 
       <div