chore(rdp): export evidence-bound hybrid timeline

[abrichr]

Summary

• Export a hash-bound hybrid timeline beside the derivative RDP MP4.
• Bind exact presentation frames, PTS intervals, retained source-frame hashes, graph nodes, and sanitized execution facts.
• Omit target geometry when the runtime did not retain a frame-exact binding.

Validation

• uv run pytest -q tests/test_rdp_ladder_qualification.py
• uv run ruff check benchmark/rdp_ladder/render_presentation.py tests/test_rdp_ladder_qualification.py
• uv run ruff format --check benchmark/rdp_ladder/render_presentation.py tests/test_rdp_ladder_qualification.py
• git diff origin/main...HEAD --check

This PR needs a regenerated RDP qualification artifact after merge. The current media remains unchanged.

[abrichr]

Independent review found that this timeline is not yet safe to publish.

Required changes:

• Use a closed, typed public-fact schema. Do not copy arbitrary source summary values or verifier strings.
• Remove source summaries, SQL rows, request values, and record identifiers from the public render manifest.
• Bind every video interval to exactly one retained authority: a hash-verified public request artifact, an exact graph binding, or an exact retained source frame.
• Reject unknown entry fields, including fabricated target geometry.
• Verify source-manifest, graph, video, and sanitized-artifact hashes against the actual bytes.
• Use frame indices plus a rational time base as the binding. Floating seconds can remain display-only.

Keep target geometry absent unless the runtime retained an exact frame binding. Treat the timeline as presentation metadata, not execution evidence.

I paused the website artifact update until a corrected exact campaign is available.