resolveModelForDelegateTask returned input.userModel immediately without
availability checking when it was set, silently ignoring the user's
configured fallback_models. Effect: a team-mode category member
(e.g. hyperplan's 'artistry' category) configured with
{ model: "opencode/gemini-3.1-pro", fallback_models: [...] }
spawned with the unreachable primary even though a listed fallback was
reachable, leading to a dropped/broken team member instead of graceful
degradation.
Now, when the provider-models cache is warm AND userFallbackModels is
non-empty, the function verifies userModel is reachable via
fuzzyMatchModel. If not, it iterates userFallbackModels and promotes the
first reachable entry. Cold-cache (first-run) behavior is preserved -
the userModel is returned as-is when availability data is unavailable,
matching the existing 'trust the user' contract covered by the
pre-cache test fixtures.
Adds three regression tests covering: (1) unreachable primary + reachable
fallback -> fallback promoted, (2) reachable primary + reachable fallback
-> primary kept (fast path), (3) unreachable primary + unreachable
fallback -> legacy trust-user behavior preserved.
Jacob Schechter
711b75345b