fix: remove public key deployment from deploy-keys

Deploy-keys now only:
- Creates /var/lib/syncserver/ssh/keys on remote
- Uploads private keys of all other machines to that path
- Populates known_hosts with all other machine hosts

No longer touches authorized_keys or reads server public key.

internal/api/handlers_machines.go

@@ -7,7 +7,6 @@ import (
 	"fmt"
 	"log/slog"
 	"net/http"
-	"os"
 	"path/filepath"
 	"regexp"
 	"strconv"
@@ -341,8 +340,8 @@ func (h *MachineHandler) DeployKeys(w http.ResponseWriter, r *http.Request) {
 	}
 
 	var req struct {
-		KnownHostsHost    string `json:"known_hosts_host"`
-		IncludeServerKey  bool   `json:"include_server_key"`
+		KnownHostsHost   string `json:"known_hosts_host"`
+		IncludeServerKey bool   `json:"include_server_key"`
 	}
 	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
 		writeError(w, http.StatusBadRequest, "invalid request body")
@@ -350,7 +349,6 @@ func (h *MachineHandler) DeployKeys(w http.ResponseWriter, r *http.Request) {
 	}
 
 	serverKeyPath := h.cfg.SSHDir() + "/id_ed25519"
-	serverPubKeyPath := h.cfg.SSHDir() + "/id_ed25519.pub"
 
 	if m.SSHKeyID != nil {
 		sshKeyRepo := models.NewSSHKeyRepository(h.db)
@@ -360,14 +358,6 @@ func (h *MachineHandler) DeployKeys(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	serverPubKey := ""
-	if req.IncludeServerKey {
-		data, err := os.ReadFile(serverPubKeyPath)
-		if err == nil {
-			serverPubKey = string(data)
-		}
-	}
-
 	allMachines, err := repo.GetAll()
 	if err != nil {
 		slog.Warn("failed to fetch machines for auto-detect", "error", err)
@@ -406,13 +396,11 @@ func (h *MachineHandler) DeployKeys(w http.ResponseWriter, r *http.Request) {
 	result, err := sshmanager.DeployKeysToMachine(
 		context.Background(),
 		serverKeyPath,
-		serverPubKey,
 		m.Host,
 		m.Port,
 		m.SSHUser,
 		keys,
 		knownHostsHosts,
-		req.IncludeServerKey,
 	)
 	if err != nil {
 		writeError(w, http.StatusInternalServerError, err.Error())