CodeQL js/polynomial-redos (alerts #765/#766).
`/\/+$/` has no left anchor, so the engine retries the match at every
start offset and each attempt re-walks the whole slash run before failing
`$` — O(n^2) on a connection baseUrl made of many slashes. Measured on
the vulnerable code: 10k slashes = 102ms, 30k = 968ms, 60k = 4028ms
(clean quadratic); through the public resolvers the same input took 22s.
providerSpecificData.baseUrl is operator-supplied config and reaches the
trim via isFamilyPresetUrl() -> normalizeEndpoint() and both resolve*Url()
helpers, so the input is reachable.
Replaces all three identical occurrences with a linear charCodeAt scan.
CodeQL only flagged two of them; the third (resolveAlibabaProviderModelsUrl)
carries the same defect and is fixed here rather than left behind.
Behavior is unchanged: every trailing slash is still removed (not a bounded
subset), interior slashes are preserved, and an all-slash string still
collapses to empty — asserted by the new behavior test.
db1f435f55