feat: automatically discover inventory (#127)

## Fully automated inventory gathering now works!

Boot up harmony_inventory_agent with `cargo run -p harmony_inventory_agent`
Launch the DiscoverInventoryAgentScore , currently available this way :

`RUST_LOG=info cargo run -p example-cli -- -f Discover -y`

And you will have automatically all hosts saved to the database. Run `cargo sqlx setup` if you have not done it yet.

Co-authored-by: Ian Letourneau <ian@noma.to>
Reviewed-on: #127
Co-authored-by: Jean-Gabriel Gill-Couture <jg@nationtech.io>
Co-committed-by: Jean-Gabriel Gill-Couture <jg@nationtech.io>

harmony_types/src/net.rs

@@ -1,6 +1,6 @@
-use serde::Serialize;
+use serde::{Deserialize, Serialize};
 
-#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, Serialize)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
 pub struct MacAddress(pub [u8; 6]);
 
 impl MacAddress {
@@ -25,6 +25,30 @@ impl std::fmt::Display for MacAddress {
     }
 }
 
+impl TryFrom<String> for MacAddress {
+    type Error = std::io::Error;
+
+    fn try_from(value: String) -> Result<Self, Self::Error> {
+        let parts: Vec<&str> = value.split(':').collect();
+        if parts.len() != 6 {
+            return Err(std::io::Error::new(
+                std::io::ErrorKind::InvalidInput,
+                "Invalid MAC address format: expected 6 colon-separated hex pairs",
+            ));
+        }
+        let mut bytes = [0u8; 6];
+        for (i, part) in parts.iter().enumerate() {
+            bytes[i] = u8::from_str_radix(part, 16).map_err(|_| {
+                std::io::Error::new(
+                    std::io::ErrorKind::InvalidInput,
+                    format!("Invalid hex value in part {}: '{}'", i, part),
+                )
+            })?;
+        }
+        Ok(MacAddress(bytes))
+    }
+}
+
 pub type IpAddress = std::net::IpAddr;
 
 #[derive(Debug, Clone)]