fix(http): append newline to debug file writes for valid jsonl format

[tusharmath]

Summary

Fix HTTP debug file writes to append a newline after each entry, ensuring the output is valid JSONL (JSON Lines) format.

Context

When the debug_requests feature is enabled, HTTP request/response bodies are appended to a debug file. However, each write was missing a trailing newline, meaning entries were written back-to-back without any delimiter. This breaks the JSONL format, where each line must be a separate, complete JSON object. Tools that consume JSONL files (log parsers, analytics pipelines, etc.) would fail to parse the debug output correctly.

Changes

• Updated ForgeHttpInfra to append a \n byte after each body write to the debug file, producing valid JSONL output.
• Updated all related unit tests to reflect the new expected output (body + newline).

Key Implementation Details

The fix is minimal and targeted: before calling file_writer.append, the body bytes are cloned into a Vec<u8>, a newline byte (b'\n') is pushed, and the result is converted back to Bytes. This ensures no existing data is mutated and the change is fully backward-compatible.

Testing

# Run the affected crate's tests
cargo insta test --accept -p forge_infra

All four existing debug-write tests have been updated to assert the newline is present and continue to pass.

Links

• Affected file: crates/forge_infra/src/http.rs