parseModelPatternWithContext ran matchModel on the whole pattern
(including a trailing :level thinking suffix) and only stripped the
suffix if that first pass missed. matchModel's provider-scoped fuzzy
match normalizes colons away and does subsequence matching, so
kimi-for-coding:high matched the longer sibling kimi-for-coding-highspeed
before the suffix was recognized as a thinking level, silently switching
model and billing tier.
Match the full pattern exactly first (new exactOnly mode skips the
fuzzy/substring fallbacks), then strip a valid :level suffix and recurse
before any fuzzy match; fuzzy-match the whole pattern only as a last
resort. Literal ids ending in :max still win via the exact pass.
Fixes#5151
roboomp
8dfbe8e09d