feat: add MCP server templates and deployment infrastructure

Introduce a Helm-chart-like template system for MCP servers. Templates are
YAML files in templates/ that get seeded into the DB on startup. Users can
browse them with `mcpctl get templates`, inspect with `mcpctl describe
template`, and instantiate with `mcpctl create server --from-template=`.

Also adds Portainer deployment scripts, mcplocal systemd service,
Streamable HTTP MCP endpoint, and RPM packaging for mcpctl-local.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/db/prisma/schema.prisma

@@ -66,6 +66,9 @@ model McpServer {
   createdAt     DateTime        @default(now())
   updatedAt     DateTime        @updatedAt
 
+  templateName    String?
+  templateVersion String?
+
   instances McpInstance[]
 
   @@index([name])
@@ -77,6 +80,28 @@ enum Transport {
   STREAMABLE_HTTP
 }
 
+// ── MCP Templates ──
+
+model McpTemplate {
+  id            String    @id @default(cuid())
+  name          String    @unique
+  version       String    @default("1.0.0")
+  description   String    @default("")
+  packageName   String?
+  dockerImage   String?
+  transport     Transport @default(STDIO)
+  repositoryUrl String?
+  externalUrl   String?
+  command       Json?
+  containerPort Int?
+  replicas      Int       @default(1)
+  env           Json      @default("[]")
+  createdAt     DateTime  @default(now())
+  updatedAt     DateTime  @updatedAt
+
+  @@index([name])
+}
+
 // ── Secrets ──
 
 model Secret {