http: expose GET /api/version

internal/server/http/version.go

@@ -0,0 +1,20 @@
+package http
+
+import (
+	"encoding/json"
+	stdhttp "net/http"
+
+	"gitea.dcglab.co.uk/steve/restic-manager/internal/version"
+)
+
+// handleVersion exposes the server's build-time identifying constants
+// (set via -ldflags). Public-band — no secrets surface here, the agent
+// updater compares its own agent_version byte-for-byte against the
+// Version field to drive the "out of date" signal.
+func (s *Server) handleVersion(w stdhttp.ResponseWriter, r *stdhttp.Request) {
+	w.Header().Set("Content-Type", "application/json")
+	_ = json.NewEncoder(w).Encode(map[string]string{
+		"version": version.Version,
+		"commit":  version.Commit,
+	})
+}