server: render calendar summary before any pre-existing text

server/Cargo.toml

@@ -12,6 +12,7 @@ version.workspace = true
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+html2text = "0.6"
 ammonia = "4.1.0"
 anyhow = "1.0.98"
 askama = { version = "0.14.0", features = ["derive"] }