fix(rpn): treat Cool values in result metric space during absorption

When Cool (Universal) absorbs into a metric, treat the Cool value as
units of the result metric, not base units.

Previously: 5 100Mbps [+] → ~110 Mbps (5 base bps is negligible)
Now:        5 100Mbps [+] → 105 Mbps (5 treated as 5 Mbps)

This makes Cool absorption intuitive: a bare number combined with a
metric-aware value is interpreted in the same unit space.

Changes:
- convertToBase now takes resultMetric param for Cool absorption
- All callers compute result metric first, then pass to convertToBase
- Updated tests to match new behavior

0 files changed, 0 insertions, 0 deletions