Function content_hash 

pub fn content_hash<T: Serialize>(value: &T) -> String

Compute a SHA256 hash of a serializable value.

The value is first serialized to JSON, then hashed. This provides a deterministic fingerprint of the content that can be used for:

• Detecting if a record has changed since last export
• Comparing local vs external records during import

Panics

Panics if the value cannot be serialized to JSON. This should never happen for our data types which are all serializable.

Example

let session = Session { id: "sess_1".into(), ... };
let hash = content_hash(&session);
// hash is something like "a1b2c3d4..."