docs: slim the agent conventions

The founding rule restated SPEC.md, which stays the source of truth
for the confinement budget. Commit bodies gain a length cap, and a
commit must build and work on its own; bisectability outranks the
one-component-per-commit split when the two collide.

crates/ecrou/Cargo.toml

@@ -15,7 +15,6 @@ serde_yaml = "0.9"
 # HTTP downloads
 reqwest = { version = "0.13", features = ["blocking", "stream"] }
 
-
 # Tarball extraction
 tar = "0.4"
 flate2 = "1"