feat: WhatsApp + LinkedIn integrations, SquareMCP rebrand, opencode docs

WhatsApp Business API (Meta Cloud API)
- New client: src/clients/whatsapp.ts
- Tools: whatsapp_send_message, whatsapp_send_template, whatsapp_list_templates
- REST endpoints: POST /api/whatsapp/send, POST /api/whatsapp/template, GET /api/whatsapp/templates
- Multi-account env var pattern: WHATSAPP_{ACCOUNT}_*

LinkedIn API (OpenID Connect)
- New client: src/clients/linkedin.ts
- Tools: linkedin_get_profile, linkedin_create_post, linkedin_search_connections, linkedin_send_message
- REST endpoints: GET /api/linkedin/profile, POST /api/linkedin/post, POST /api/linkedin/search-connections, POST /api/linkedin/message
- Multi-account env var pattern: LINKEDIN_{ACCOUNT}_*
- Uses /v2/userinfo (OpenID Connect) for profile reads

Domain migration
- hermes.fetcherpay.com -> hermes.squaremcp.com
- Updated K8s ingress, TLS cert, SERVER_URL env var
- Updated OPENCODE.md and opencode.json references

SquareMCP site
- Added logo assets (SVG, LinkedIn variants)
- Added terms.html
- Updated Dockerfile, nginx config, styles, index, privacy pages

Docs
- Added OPENCODE.md for opencode AI integration setup
- Updated .env.example with WhatsApp and LinkedIn credentials
- Added opencode.json to .gitignore (contains live API key)

Total tools: 19 (email 6, obsidian 5, whatsapp 4, linkedin 4)

product/site/styles.css

@@ -58,15 +58,11 @@ a {
   font-weight: 800;
 }
 
-.brand-mark {
-  display: inline-flex;
-  align-items: center;
-  justify-content: center;
-  width: 30px;
-  height: 30px;
-  border-radius: 8px;
-  background: var(--accent);
-  color: #fff;
+.brand-logo {
+  display: block;
+  width: 34px;
+  height: 34px;
+  flex: 0 0 auto;
 }
 
 .brand-text {
@@ -465,6 +461,72 @@ textarea:focus {
   flex-wrap: wrap;
 }
 
+.legal-shell {
+  min-height: 100vh;
+  background:
+    radial-gradient(circle at top right, #d9e6ff 0%, transparent 24%),
+    linear-gradient(180deg, #f8fbff 0%, #eef3fb 100%);
+}
+
+.legal-main {
+  padding: 40px 0 64px;
+}
+
+.legal-card {
+  width: min(860px, calc(100% - 32px));
+  margin: 0 auto;
+  padding: 28px;
+  background: var(--surface);
+  border: 1px solid var(--line);
+  border-radius: 12px;
+  box-shadow: 0 18px 40px rgba(22, 41, 76, 0.08);
+}
+
+.legal-eyebrow {
+  margin-bottom: 10px;
+  color: var(--accent-strong);
+  font-size: 13px;
+  font-weight: 700;
+  text-transform: uppercase;
+}
+
+.legal-title {
+  margin-bottom: 8px;
+}
+
+.legal-subhead {
+  margin: 0 0 28px;
+  color: var(--muted);
+  font-size: 15px;
+}
+
+.legal-section + .legal-section {
+  margin-top: 28px;
+}
+
+.legal-section h2 {
+  margin-bottom: 10px;
+  font-size: 24px;
+}
+
+.legal-section p,
+.legal-section li {
+  color: var(--muted);
+}
+
+.legal-section ul {
+  margin: 0;
+  padding-left: 20px;
+}
+
+.legal-note {
+  margin-top: 28px;
+  padding: 16px 18px;
+  border-radius: 10px;
+  background: var(--accent-soft);
+  color: var(--text);
+}
+
 @media (max-width: 980px) {
   h1 {
     font-size: 42px;
@@ -517,4 +579,16 @@ textarea:focus {
   .band {
     padding: 44px 0;
   }
+
+  .legal-main {
+    padding: 28px 0 48px;
+  }
+
+  .legal-card {
+    padding: 22px;
+  }
+
+  .legal-section h2 {
+    font-size: 22px;
+  }
 }