feat(brand): chemistry rebrand across panel + marketing

The logged-in panel is now Catalyst Console (by Corrosion); the marketing site
keeps Corrosion as the platform/company and introduces the lexicon.

- Wordmark: panel/auth Logo lockup -> 'Catalyst' / 'by Corrosion'; the shared
  C-core house mark (CorrosionMark) is untouched. Marketing nav/footer keep the
  'Corrosion' wordmark.
- Titles: panel routes -> '{View} · Catalyst'; auth -> Catalyst; document.title
  fallback + index.html -> 'Catalyst Console'. Marketing titles stay '— Corrosion'.
- Host agent user-facing copy -> 're-Agent' across panel + marketing (the
  binary filename / CDN URLs / config paths / domains are UNCHANGED — that's the
  separate infra/binary-rename sprint; 'Download re-Agent' fetching
  corrosion-host-agent-* is the intended intermediate state).
- Deploy-recipe 'blueprint/template' -> 'Formula/Formulae' in marketing + roadmap;
  Rust in-game 'blueprint wipe' kept (game term).
- docs/BRANDING.md added (Oracle review + locked lexicon).

vue-tsc + vite green; rendered clean both faces (Catalyst panel / Corrosion
marketing), 0 console errors.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/views/admin/DashboardView.vue

@@ -259,7 +259,7 @@ function navServer() { router.push('/server') }
         <EmptyState
           icon="server"
           title="No server connected"
-          description="Install the Corrosion host agent on your host machine to begin managing your server from Corrosion."
+          description="Install re-Agent on your host machine to begin managing your server from Catalyst."
         >
           <template #action>
             <Button icon="server" @click="navServer">Set up server</Button>
@@ -404,7 +404,7 @@ function navServer() { router.push('/server') }
         <div class="dash__col dash__col--side">
 
           <!-- Resources — real stats from agent; null = '—' -->
-          <Panel title="Resources" subtitle="Host agent telemetry">
+          <Panel title="Resources" subtitle="re-Agent telemetry">
             <div class="solo-meters">
               <ResourceMeter
                 label="CPU"
@@ -418,7 +418,7 @@ function navServer() { router.push('/server') }
               />
             </div>
             <div v-if="soloCpu === null && soloRamMb === null" class="meters-note">
-              Resource metrics arrive via the host agent heartbeat.
+              Resource metrics arrive via re-Agent heartbeat.
               <Button size="sm" variant="ghost" icon="server" class="meters-cta" @click="navServer">
                 Agent setup
               </Button>