Preserve exact diff bytes and current CI truth

[JetXu-LLM]

Why

The first post-open-source LlamaPReview quality audit found two retrieval-owner defects in the exact released llama-github==0.4.5 wheel:

• new/deleted-file diff generation inserted a synthetic space after +/-, turning a column-zero source line into an apparently indented line;
• check-run retrieval relied on implicit latest-attempt behavior and omitted stable app/suite/run identity needed to reconcile attempts without merging distinct workflows.

Change

• emit standard unified diff markers without inserting source whitespace;
• request filter="latest", retain stable run/app/suite identity, and reconcile only attempts with the same app/suite/name identity;
• use intentional bounded page reads with page counts, explicit truncation, independent CI-surface errors, and retention of already observed evidence;
• preserve equal check names from distinct apps or suites;
• release metadata advances to 0.4.6.

Evidence

• Python 3.11: 143 tests passed
• Python 3.12: 143 tests passed
• focused retrieval/diff tests: 103 passed
• compile, diff check, package build, Twine validation, and exact wheel-content verification passed

Adversarial coverage includes over-100 status/check collections, later-page failure, permission denial on one CI surface, stale failure/success attempts in both directions, duplicate names from distinct workflows/apps, all relevant GitHub check states, and source indentation versus diff decoration.

This is a general SDK correction; no LlamaPReview-specific repository or check-name rules are introduced.