feat(jobs): add durable PG queue reclaim, slog, and richer metrics

JSON slog в ключевых пакетах; Prometheus path_group, job_audit_depth, upstream breaker; job_audit ClaimQueued/ReclaimStaleRunning + Adopt loop для HA после рестарта.

Co-authored-by: Cursor <[email protected]>

internal/logging/logger.go

@@ -0,0 +1,38 @@
+// Package logging provides a process-wide slog JSON logger for EvoBGP binaries.
+package logging
+
+import (
+	"log/slog"
+	"os"
+	"strings"
+	"sync"
+)
+
+var (
+	once   sync.Once
+	logger *slog.Logger
+)
+
+// Default returns the process JSON slog logger (stdout). Level from EVOBGP_LOG_LEVEL (debug|info|warn|error).
+func Default() *slog.Logger {
+	once.Do(func() {
+		level := slog.LevelInfo
+		switch strings.ToLower(strings.TrimSpace(os.Getenv("EVOBGP_LOG_LEVEL"))) {
+		case "debug":
+			level = slog.LevelDebug
+		case "warn", "warning":
+			level = slog.LevelWarn
+		case "error":
+			level = slog.LevelError
+		}
+		handler := slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: level})
+		logger = slog.New(handler)
+		slog.SetDefault(logger)
+	})
+	return logger
+}
+
+// With returns Default().With(args...).
+func With(args ...any) *slog.Logger {
+	return Default().With(args...)
+}