P7: restore agent node type, agent heartbeat expiry, build-version injection, remove log/history/xray-metrics modules, optional sub port

- nodes: port node-type (traditional/agent) picker back from web-src into
  the embedded frontend; backend annotates NodeView.nodeType from
  agent_nodes bindings; fix agent-node update path (skip reachability
  probe and apiToken requirement for agent-managed nodes); restore i18n
  keys in all 13 locales; install command now uses the Gitea mirror
- jobs: expire agent-bound nodes whose agent_nodes.last_seen is older
  than max(3x heartbeat interval, 120s) = 180s; last_seen=0 (never
  registered) is left untouched; transitions reuse UpdateHeartbeat +
  node event broadcast
- config: GetBaseVersion honors ldflags-injected buildVersion; release
  builds inject 3.7.0-agent.1 so the panel no longer reports a phantom
  update against the Gitea release tag
- logger/server: remove the three log viewers (panel/xray/amneziawg),
  their API endpoints and the 10240-entry in-memory log buffer; file
  logging via lumberjack unchanged; tests assert via a new optional
  logger hook instead of the removed buffer
- server: remove system history and xray metrics modules end to end
  (endpoints, sampling appends in RefreshStatus, per-minute persist
  cron, gob snapshot/restore, XrayMetricsService); realtime status and
  per-node history are untouched
- settings: subPort may be 0/unset - subscription links are generated
  without a port while the subscription service keeps binding the
  default 2096; the settings form declares the cleared state via
  onNumber's new onClear option instead of snapping back to 1

internal/logger/logger_test.go

@@ -2,29 +2,47 @@ package logger
 
 import (
 	"fmt"
+	"sync"
 	"testing"
 )
 
-// TestGetLogs_ReturnsAtMostC guards the documented "up to c entries" contract.
-// The loop condition must cap output at c (ERROR entries are queried at "debug"
-// level so the level filter passes all of them, isolating the count).
-func TestGetLogs_ReturnsAtMostC(t *testing.T) {
-	logBufferMu.Lock()
-	logBuffer = nil
-	logBufferMu.Unlock()
-	for i := range 5 {
-		addToBuffer("ERROR", fmt.Sprintf("m%d", i))
-	}
+// TestLogHookReceivesEntries replaces the old in-memory buffer tests: the
+// buffer (and its GetLogs accessor) was removed with the web log viewer, and
+// the hook is now the only side channel tests assert on.
+func TestLogHookReceivesEntries(t *testing.T) {
+	var mu sync.Mutex
+	var got []string
+	prev := SetLogHook(func(level, msg string) {
+		mu.Lock()
+		defer mu.Unlock()
+		got = append(got, level+" "+msg)
+	})
+	t.Cleanup(func() { SetLogHook(prev) })
 
-	cases := []struct{ c, want int }{
-		{0, 0},
-		{2, 2},
-		{5, 5},
-		{10, 5}, // capped at what's available
+	Debug("d1")
+	Infof("i%d", 2)
+	Warning("w3")
+	Errorf("e%s", "4")
+
+	want := []string{"DEBUG d1", "INFO i2", "WARNING w3", "ERROR e4"}
+	mu.Lock()
+	defer mu.Unlock()
+	if len(got) != len(want) {
+		t.Fatalf("hook captured %v, want %v", got, want)
 	}
-	for _, tc := range cases {
-		if got := GetLogs(tc.c, "debug"); len(got) != tc.want {
-			t.Errorf("GetLogs(%d) returned %d entries, want %d", tc.c, len(got), tc.want)
+	for i := range want {
+		if got[i] != want[i] {
+			t.Fatalf("hook entry %d = %q, want %q", i, got[i], want[i])
 		}
 	}
 }
+
+// TestLogHookUnsetIsSilent guards the production path: with no hook
+// installed, logging must simply not panic.
+func TestLogHookUnsetIsSilent(t *testing.T) {
+	prev := SetLogHook(nil)
+	t.Cleanup(func() { SetLogHook(prev) })
+	for i := range 3 {
+		Info(fmt.Sprintf("m%d", i))
+	}
+}