Fix SourceHunt managed-run handoffs

[ropoctl]

Summary

• forward a bounded campaign hint from the machine request into SourceHuntRunner
• accept compatibility traces emitted as JSON strings and normalize them before use
• reserve the final hunter turn for a tool-free synthesis so successful work is not lost at the step boundary

Stack

• Depends on fix(sourcehunt): bound machine progress records #206.
• The PR base is the fix(sourcehunt): bound machine progress records #206 branch so this review contains only the extracted six-file Clearwing delta.
• Merge fix(sourcehunt): bound machine progress records #206 before this PR; after fix(sourcehunt): bound machine progress records #206 lands, retarget this PR to main if GitHub does not do so automatically.

Validation

• Focused regression suites: 125 passed
• Ruff lint on all six changed files: passed
• Wheel and sdist build plus twine validation: passed
• Full non-strict suite: 3,328 passed, 2 skipped; 7 Docker integration tests failed because no Docker socket was available

The repository-wide gate is already red on the #206 base before this delta: 114 Ruff violations in unrelated code, 168 scoped mypy errors, and strict pytest collection rejects the unregistered integration marker. The extracted regression suites pass under strict configuration when selected directly.

Conflict and architecture scan

• Simulated merges are clean with Make SourceHunt sandbox execution pluggable #200, fix(sourcehunt): reserve a per-band minimum when cutting large-repo ranker candidates #201, and fix(sourcehunt): anchor rejecting verdicts to a source location #203 through feat(live): determinate progress bars for preprocess & rank #207, including the direct reporting overlap in fix(sourcehunt): bound persisted trace-step payloads #205.
• fix(sourcehunt): stop a hunter that makes no new progress for N steps #202 has one content conflict in NativeHunter.arun because both branches edit termination control. The intended integration is to retain fix(sourcehunt): stop a hunter that makes no new progress for N steps #202 steps_since_progress stop argument and this PR final-synthesis injection plus tool suppression; the behaviors are complementary.
• fix(sourcehunt): restore reliable reads and callgraph coverage #190 has broader conflicts in the hunter and machine command and is already merge-dirty against main. It represents a much larger parallel SourceHunt lifecycle change and needs dedicated reconciliation if revived; this focused fix intentionally does not absorb that architecture.