fix(process): resume buffered NDJSON frames on partial chunks - #8909

Problem

When a response consumer stops iteration, complete lines remain buffered. A subsequent chunk without a newline returns early even though an older complete response is ready. Hopper's recovery path can therefore delay a buffered reply until an unrelated later response supplies another newline.

Changes

Track the next buffered newline before yielding a line. Resume delivery when complete buffered lines exist, including on a partial or empty push, and clear that state on reset. Incomplete fragments still accumulate without rescanning or joining them on every push.

The shared decoded NDJSON splitter remains the owner of framing; Hopper retains its response validation and abort policy. The Ghidra consumer continues to drain all available lines.

Validation

• DecodedNdjsonLineBuffer.test.ts and HopperResponseStream.test.ts: 6 passed on Node 24.22.1 / Vitest 5.0.3, with a focused external test configuration.
• Coverage includes recovery after malformed JSON and a future response ID, buffered delivery before a later response is complete, empty-push draining, and reset.
• Re-running against the unmodified source: 3 failed, 3 passed.
• Targeted TypeScript 5.9.3 checking, repository-pinned oxfmt 0.72.0 formatting, and git diff --check passed.

These are parser and production-response-stream tests. The full project checks and a live Hopper/Ghidra session were not run.

Author readiness

Human owner: @Afloat16

• I reviewed the final diff and relevant existing code, understand the change and its edge cases, and take responsibility for the complete PR, including AI-assisted work.
• I checked the evidence above, confirmed it supports the current change, and recorded meaningful validation gaps.
• I declare this PR ready for initial maintainer review.