A new draft session inherited the previous session's model/agent instead of
resetting to defaults, because opening a draft restored the directory snapshot
without re-applying the startup default cascade. When the prior session ran in
a worktree, defaults were resolved against the worktree directory's provider
list, which omits project/global-scoped providers, so the default agent's model
fell back to opencode/big-pickle.
Resolve the default agent/model via a shared cascade (settings default ->
OpenCode default_agent -> build -> first), resolve the model from the agent's
pinned model/variant or OpenCode's config model, and activate the project's
config (not the worktree's) when opening a draft.
Bohdan Triapitsyn
9111611bdc