feat: publish Gamertan Web Foundations preview source

Export the reviewed application-neutral package set through the exact public allowlist. Development history and private application evidence remain outside this canonical source root.

Developed with material AI assistance under maintainer review.

Signed-off-by: Cole Speelman <crspeelman@gmail.com>

requestlog/jsonl.go

@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: MPL-2.0
+
+package requestlog
+
+import (
+	"bufio"
+	"context"
+	"encoding/json"
+	"errors"
+	"os"
+	"path/filepath"
+	"sync"
+)
+
+// JSONL is a synchronous append-only sink. The caller owns rotation.
+type JSONL struct {
+	mu     sync.Mutex
+	file   *os.File
+	writer *bufio.Writer
+	err    error
+}
+
+func OpenJSONL(path string) (*JSONL, error) {
+	if !filepath.IsAbs(path) || filepath.Clean(path) != path {
+		return nil, errors.New("requestlog: JSONL path must be clean and absolute")
+	}
+	if info, err := os.Lstat(path); err == nil && (info.Mode()&os.ModeSymlink != 0 || !info.Mode().IsRegular()) {
+		return nil, errors.New("requestlog: JSONL destination must be a regular file")
+	} else if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return nil, err
+	}
+	file, err := os.OpenFile(path, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0o600)
+	if err != nil {
+		return nil, err
+	}
+	if err = file.Chmod(0o600); err != nil {
+		file.Close()
+		return nil, err
+	}
+	return &JSONL{file: file, writer: bufio.NewWriterSize(file, 64*1024)}, nil
+}
+
+func (sink *JSONL) WriteRecord(ctx context.Context, record Record) error {
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+	if err := record.Validate(); err != nil {
+		return err
+	}
+	body, err := json.Marshal(record)
+	if err != nil {
+		return err
+	}
+	sink.mu.Lock()
+	defer sink.mu.Unlock()
+	if sink.err != nil {
+		return sink.err
+	}
+	if _, err = sink.writer.Write(append(body, '\n')); err == nil {
+		err = sink.writer.Flush()
+	}
+	if err != nil {
+		sink.err = err
+	}
+	return err
+}
+
+func (sink *JSONL) Err() error { sink.mu.Lock(); defer sink.mu.Unlock(); return sink.err }
+
+func (sink *JSONL) Close() error {
+	sink.mu.Lock()
+	defer sink.mu.Unlock()
+	if sink.file == nil {
+		return sink.err
+	}
+	flushErr := sink.writer.Flush()
+	closeErr := sink.file.Close()
+	sink.file = nil
+	return errors.Join(sink.err, flushErr, closeErr)
+}