fix: load system fonts for OG image text rendering

usvg's default Options creates an empty fontdb, so no fonts are found
for text rendering regardless of what's installed. Load system fonts
into a fontdb::Database and set the default font family to Noto Sans.

Also picks up a formatting change to index.html from a linter.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Cargo.toml

@@ -31,6 +31,7 @@ reqwest = { version = "0.12", default-features = false, features = ["rustls-tls"
 figment = { version = "0.10", features = ["toml", "env"] }
 clap = { version = "4", features = ["derive", "env"] }
 resvg = "0.45"
+fontdb = "0.23"
 
 # internal
 moments-entities = { path = "crates/moments-entities", version = "=0.1.0" }