swarm-secret-client: derive Kind's segment strings via strum instead of a hand-written match

swarm-secret-client/src/path.rs

@@ -25,19 +25,28 @@ pub const ROOT: &str = "swarm";
 /// misspelled kind is a 403 at provision time rather than anything a compiler
 /// sees. [`Kind::ALL`] exists so a test can enumerate the set instead of
 /// restating it.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+///
+/// The segment string lives once, on the variant itself
+/// (`#[strum(serialize = "...")]`), rather than a second time in a
+/// hand-written `as_str()` match — [`strum::IntoStaticStr`] derives that
+/// conversion, so the attribute is the only place a segment is spelled.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, strum::IntoStaticStr)]
 pub enum Kind {
     /// One agent container's own secrets.
+    #[strum(serialize = "agents")]
     Agent,
     /// One hive's secrets, held on behalf of whatever runs there. An identity
     /// minted per hive rather than per agent lands here even though an agent
     /// is what uses it.
+    #[strum(serialize = "hives")]
     Hive,
     /// One swarm service — the things a swarm runs beside the controller.
+    #[strum(serialize = "services")]
     Service,
     /// The controller itself. There is one per swarm, so the name segment
     /// below it does not vary; the shape stays uniform anyway, because one
     /// grant pattern over `<kind>/<name>` is cheaper than a special case.
+    #[strum(serialize = "controller")]
     Controller,
 }
 
@@ -47,15 +56,11 @@ impl Kind {
     pub const ALL: [Kind; 4] = [Kind::Agent, Kind::Hive, Kind::Service, Kind::Controller];
 
     /// The path segment, which is also what the store's grant is written
-    /// against.
+    /// against. Thin wrapper over the derived `Into<&'static str>` so call
+    /// sites keep the same method-call shape as before.
     #[must_use]
-    pub const fn as_str(self) -> &'static str {
-        match self {
-            Kind::Agent => "agents",
-            Kind::Hive => "hives",
-            Kind::Service => "services",
-            Kind::Controller => "controller",
-        }
+    pub fn as_str(self) -> &'static str {
+        self.into()
     }
 
     /// What to call the name in an error — singular, because the message reads