refactor: ApprovalKind::as_str owns the kind→string mapping

replaces three hand-rolled six-arm matches (actions.rs ×2,
state_snapshot.rs); approvals::kind_to_str delegates. a new kind can
no longer silently miss one of them

hive-c0re/src/actions.rs

@@ -540,14 +540,7 @@ fn finish_approval(
     // snapshot refetch. `approved` rows that succeed get the
     // approval's logged resolved_at indirectly via `now_unix()`;
     // failures already wrote it via mark_failed above.
-    let approval_kind = match approval.kind {
-        ApprovalKind::Spawn => "spawn",
-        ApprovalKind::ApplyCommit => "apply_commit",
-        ApprovalKind::InitConfig => "init_config",
-        ApprovalKind::UpdateMetaInputs => "update_meta_inputs",
-        ApprovalKind::SchedulePrompt => "schedule_prompt",
-        ApprovalKind::MergeConfigPr => "merge_config_pr",
-    };
+    let approval_kind = approval.kind.as_str();
     let sha_short = approval
         .fetched_sha
         .as_deref()
@@ -1021,14 +1014,7 @@ pub async fn deny(coord: &Coordinator, id: i64, note: Option<&str>) -> Result<()
                 tracing::warn!(%id, agent = %a.agent, error = ?e, "forge: push_config after deny failed");
             }
         }
-        let approval_kind = match a.kind {
-            ApprovalKind::Spawn => "spawn",
-            ApprovalKind::ApplyCommit => "apply_commit",
-            ApprovalKind::InitConfig => "init_config",
-            ApprovalKind::UpdateMetaInputs => "update_meta_inputs",
-            ApprovalKind::SchedulePrompt => "schedule_prompt",
-            ApprovalKind::MergeConfigPr => "merge_config_pr",
-        };
+        let approval_kind = a.kind.as_str();
         let sha_short = sha.as_deref().map(|s| s[..s.len().min(12)].to_owned());
         let description = a.description.clone();
         let agent_owned = a.agent.clone();

hive-c0re/src/approvals.rs

@@ -411,18 +411,11 @@ fn row_to_approval(row: &rusqlite::Row<'_>) -> rusqlite::Result<Approval> {
 }
 
 /// Stable kind→str mapping used wherever we emit `ApprovalResolved`
-/// or persist a kind to sqlite. `pub(crate)` so callers like
-/// `questions::handle_cancel_loose_end` don't have to duplicate the
-/// match; bumping a kind here is the single source of truth.
+/// or persist a kind to sqlite. Thin alias over
+/// [`ApprovalKind::as_str`] (the wire-type owns the mapping) kept for
+/// the existing call sites' name.
 pub(crate) fn kind_to_str(kind: ApprovalKind) -> &'static str {
-    match kind {
-        ApprovalKind::ApplyCommit => "apply_commit",
-        ApprovalKind::Spawn => "spawn",
-        ApprovalKind::InitConfig => "init_config",
-        ApprovalKind::UpdateMetaInputs => "update_meta_inputs",
-        ApprovalKind::SchedulePrompt => "schedule_prompt",
-        ApprovalKind::MergeConfigPr => "merge_config_pr",
-    }
+    kind.as_str()
 }
 
 fn kind_from_str(s: &str) -> Result<ApprovalKind> {

hive-c0re/src/dashboard/state_snapshot.rs

@@ -526,14 +526,7 @@ fn history_view(a: Approval) -> ApprovalHistoryView {
         // Pending shouldn't appear in recent_resolved, but be defensive.
         hive_sh4re::ApprovalStatus::Pending => "pending",
     };
-    let kind = match a.kind {
-        hive_sh4re::ApprovalKind::ApplyCommit => "apply_commit",
-        hive_sh4re::ApprovalKind::Spawn => "spawn",
-        hive_sh4re::ApprovalKind::InitConfig => "init_config",
-        hive_sh4re::ApprovalKind::UpdateMetaInputs => "update_meta_inputs",
-        hive_sh4re::ApprovalKind::SchedulePrompt => "schedule_prompt",
-        hive_sh4re::ApprovalKind::MergeConfigPr => "merge_config_pr",
-    };
+    let kind = a.kind.as_str();
     ApprovalHistoryView {
         id: a.id,
         agent: a.agent,

hive-sh4re/src/lib.rs

@@ -250,6 +250,24 @@ pub enum ApprovalKind {
     MergeConfigPr,
 }
 
+impl ApprovalKind {
+    /// Wire/UI string — the same value serde's `snake_case` rename
+    /// produces. The single source of truth for every place that needs
+    /// the kind as a `&'static str` (sqlite storage, dashboard events),
+    /// so adding a variant can't silently miss a hand-rolled match.
+    #[must_use]
+    pub fn as_str(self) -> &'static str {
+        match self {
+            ApprovalKind::ApplyCommit => "apply_commit",
+            ApprovalKind::Spawn => "spawn",
+            ApprovalKind::InitConfig => "init_config",
+            ApprovalKind::UpdateMetaInputs => "update_meta_inputs",
+            ApprovalKind::SchedulePrompt => "schedule_prompt",
+            ApprovalKind::MergeConfigPr => "merge_config_pr",
+        }
+    }
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
 #[serde(rename_all = "snake_case")]
 pub enum ApprovalStatus {