refactor(operator-trend): extract _build_resolution_trend payload assembly to its own module (T3-2 phase 8b)

The 1,676-line payload.update({...}) that assembled the 320+ resolution-trend
payload keys moves verbatim into operator_trend_resolution_payload.build_resolution_trend_payload.
The god-function drops 1,852 -> 157 lines: it now reads as a clear pipeline
(run-context -> targets -> apply-chain -> summary-context -> topline payload ->
recovery-tier payload update). The helper re-derives its locals from the
apply-chain / summary-context dicts and takes the three in-module summary
renderers as injected callables (the established no-circular-import pattern;
matches the already-extracted run-context / apply-chain / summary-context /
topline-payload stages).

Pure relocation, proven byte-identical by the characterization net
(tests/test_resolution_trend_golden_contract.py) plus the full suite.

Verify: ruff clean; mypy clean on both files; 2541 passed, 2 skipped.

Author: saagpatel