Implement BBolt ImportEventsFromReader for migration (v0.48.1)

- Add import-export.go with full JSONL import support for bbolt
- Remove Import/Export/ImportEventsFromReader stubs from stubs.go
- Includes batched write flush after import completion
- Progress logging every 5 seconds during import

Files modified:
- pkg/bbolt/import-export.go: New file with import functionality
- pkg/bbolt/stubs.go: Remove implemented stubs
- pkg/version/version: v0.48.0 -> v0.48.1

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

pkg/bbolt/import-export.go

@@ -0,0 +1,192 @@
+//go:build !(js && wasm)
+
+package bbolt
+
+import (
+	"bufio"
+	"context"
+	"io"
+	"os"
+	"runtime/debug"
+	"strings"
+	"time"
+
+	"lol.mleku.dev/chk"
+	"lol.mleku.dev/log"
+
+	"git.mleku.dev/mleku/nostr/encoders/event"
+)
+
+const maxLen = 500000000
+
+// ImportEventsFromReader imports events from an io.Reader containing JSONL data
+func (b *B) ImportEventsFromReader(ctx context.Context, rr io.Reader) error {
+	startTime := time.Now()
+	log.I.F("bbolt import: starting import operation")
+
+	// Store to disk so we can return fast
+	tmpPath := os.TempDir() + string(os.PathSeparator) + "orly"
+	os.MkdirAll(tmpPath, 0700)
+	tmp, err := os.CreateTemp(tmpPath, "")
+	if chk.E(err) {
+		return err
+	}
+	defer os.Remove(tmp.Name()) // Clean up temp file when done
+
+	log.I.F("bbolt import: buffering upload to %s", tmp.Name())
+	bufferStart := time.Now()
+	bytesBuffered, err := io.Copy(tmp, rr)
+	if chk.E(err) {
+		return err
+	}
+	bufferElapsed := time.Since(bufferStart)
+	log.I.F("bbolt import: buffered %.2f MB in %v (%.2f MB/sec)",
+		float64(bytesBuffered)/1024/1024, bufferElapsed.Round(time.Millisecond),
+		float64(bytesBuffered)/bufferElapsed.Seconds()/1024/1024)
+
+	if _, err = tmp.Seek(0, 0); chk.E(err) {
+		return err
+	}
+
+	processErr := b.processJSONLEvents(ctx, tmp)
+
+	totalElapsed := time.Since(startTime)
+	log.I.F("bbolt import: total operation time: %v", totalElapsed.Round(time.Millisecond))
+
+	return processErr
+}
+
+// ImportEventsFromStrings imports events from a slice of JSON strings with policy filtering
+func (b *B) ImportEventsFromStrings(ctx context.Context, eventJSONs []string, policyManager interface {
+	CheckPolicy(action string, ev *event.E, pubkey []byte, remote string) (bool, error)
+}) error {
+	// Create a reader from the string slice
+	reader := strings.NewReader(strings.Join(eventJSONs, "\n"))
+	return b.processJSONLEventsWithPolicy(ctx, reader, policyManager)
+}
+
+// processJSONLEvents processes JSONL events from a reader
+func (b *B) processJSONLEvents(ctx context.Context, rr io.Reader) error {
+	return b.processJSONLEventsWithPolicy(ctx, rr, nil)
+}
+
+// processJSONLEventsWithPolicy processes JSONL events from a reader with optional policy filtering
+func (b *B) processJSONLEventsWithPolicy(ctx context.Context, rr io.Reader, policyManager interface {
+	CheckPolicy(action string, ev *event.E, pubkey []byte, remote string) (bool, error)
+}) error {
+	// Create a scanner to read the buffer line by line
+	scan := bufio.NewScanner(rr)
+	scanBuf := make([]byte, maxLen)
+	scan.Buffer(scanBuf, maxLen)
+
+	// Performance tracking
+	startTime := time.Now()
+	lastLogTime := startTime
+	const logInterval = 5 * time.Second
+
+	var count, total, skipped, policyRejected, unmarshalErrors, saveErrors int
+	for scan.Scan() {
+		select {
+		case <-ctx.Done():
+			log.I.F("bbolt import: context closed after %d events", count)
+			return ctx.Err()
+		default:
+		}
+
+		line := scan.Bytes()
+		total += len(line) + 1
+		if len(line) < 1 {
+			skipped++
+			continue
+		}
+
+		ev := event.New()
+		if _, err := ev.Unmarshal(line); err != nil {
+			// return the pooled buffer on error
+			ev.Free()
+			unmarshalErrors++
+			log.W.F("bbolt import: failed to unmarshal event: %v", err)
+			continue
+		}
+
+		// Apply policy checking if policy manager is provided
+		if policyManager != nil {
+			// For sync imports, we treat events as coming from system/trusted source
+			// Use nil pubkey and empty remote to indicate system-level import
+			allowed, policyErr := policyManager.CheckPolicy("write", ev, nil, "")
+			if policyErr != nil {
+				log.W.F("bbolt import: policy check failed for event %x: %v", ev.ID, policyErr)
+				ev.Free()
+				policyRejected++
+				continue
+			}
+			if !allowed {
+				log.D.F("bbolt import: policy rejected event %x during sync import", ev.ID)
+				ev.Free()
+				policyRejected++
+				continue
+			}
+			log.D.F("bbolt import: policy allowed event %x during sync import", ev.ID)
+		}
+
+		if _, err := b.SaveEvent(ctx, ev); err != nil {
+			// return the pooled buffer on error paths too
+			ev.Free()
+			saveErrors++
+			log.W.F("bbolt import: failed to save event: %v", err)
+			continue
+		}
+
+		// return the pooled buffer after successful save
+		ev.Free()
+		line = nil
+		count++
+
+		// Progress logging every logInterval
+		if time.Since(lastLogTime) >= logInterval {
+			elapsed := time.Since(startTime)
+			eventsPerSec := float64(count) / elapsed.Seconds()
+			mbPerSec := float64(total) / elapsed.Seconds() / 1024 / 1024
+			log.I.F("bbolt import: progress %d events saved, %.2f MB read, %.0f events/sec, %.2f MB/sec",
+				count, float64(total)/1024/1024, eventsPerSec, mbPerSec)
+			lastLogTime = time.Now()
+			debug.FreeOSMemory()
+		}
+	}
+
+	// Flush any remaining batched events
+	if b.batcher != nil {
+		b.batcher.Flush()
+	}
+
+	// Final summary
+	elapsed := time.Since(startTime)
+	eventsPerSec := float64(count) / elapsed.Seconds()
+	mbPerSec := float64(total) / elapsed.Seconds() / 1024 / 1024
+	log.I.F("bbolt import: completed - %d events saved, %.2f MB in %v (%.0f events/sec, %.2f MB/sec)",
+		count, float64(total)/1024/1024, elapsed.Round(time.Millisecond), eventsPerSec, mbPerSec)
+	if unmarshalErrors > 0 || saveErrors > 0 || policyRejected > 0 || skipped > 0 {
+		log.I.F("bbolt import: stats - %d unmarshal errors, %d save errors, %d policy rejected, %d skipped empty lines",
+			unmarshalErrors, saveErrors, policyRejected, skipped)
+	}
+
+	if err := scan.Err(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Import imports events from a reader (legacy interface).
+func (b *B) Import(rr io.Reader) {
+	ctx := context.Background()
+	if err := b.ImportEventsFromReader(ctx, rr); err != nil {
+		log.E.F("bbolt import: error: %v", err)
+	}
+}
+
+// Export exports events to a writer.
+func (b *B) Export(c context.Context, w io.Writer, pubkeys ...[]byte) {
+	// TODO: Implement export functionality
+	log.W.F("bbolt export: not yet implemented")
+}