Resolves an action addressed through a dynamic action provider, given a
parsedKey whose dynamicActionHost is set. Returns null when the host
is not a registered provider, the name is a wildcard (which addresses
many actions, not one), or the provider cannot resolve it.
Returns every action that can be resolved, keyed by registry key, with
dynamic action providers expanded into their individual actions. Used by
the reflection API / Dev UI so DAP-provided tools, prompts, and resources
are individually listable. Mirrors JS's listResolvableActions.
Resolves an action from a full registry key string, handling both plain
keys (/model/googleai/gemini-flash-latest) and dynamic-action-provider
keys (/dynamic-action-provider/<host>:<actionType>/<name>). Mirrors JS's
key-based lookupAction, which the Dev UI relies on to run DAP-expanded
actions (their keys are the DAP keys returned by listResolvableActions).