fix(quickadapter): make best params pair-safe (#183)

fix(quickadapter): make best params pair-safe (#183)

* fix(quickadapter): make best params pair-safe

* style(quickadapter): order pair_to_filename import per isort

Place the freqtrade.misc import after the straight third-party imports so the block satisfies ruff's isort ordering (I001), which the pair-safe best-params change had regressed. No behavior change.

* docs(quickadapter): drop internal best-params filename details from warm_start

The warm_start tunable description exposed the on-disk best-params filename convention and legacy base-only cold-start handling: internal implementation detail with no bearing on setting the tunable (AGENTS.md: omit internal details unless necessary for usage). Revert the row to its pre-change wording; the pair-safe fix needs no tunable-doc change.