Run pipeline

Start a pipeline run in the background and return its runId immediately. Video pipelines take minutes; poll get_run for progress. Runs consume account credits. inputs is keyed by entry node id (get_pipeline lists them as entryNodes): a Text Input node takes text, an HTTP Payload node takes a JSON value, and a File node takes a URL that overrides the file placed on the canvas, so a clipping pipeline can be pointed at a new source video per run without editing the graph. An entry node left out runs with the value saved on the canvas; one with nothing saved is refused, so pass it (or "" to leave it blank on purpose), and ask the user what it should say when the request does not tell you. A key that names no entry node is refused before anything runs or is charged. Before running a pipeline you built or changed in this conversation, call estimate_run_cost, wait for the person to accept the price, and pass its quoteId here: the run starts only if the pipeline is still the one quoted, and only once, so calling again with the same quoteId (a retry, a second "yes") returns the run already started instead of charging for another. Without a quote, pass a requestId of your own for the same protection on a retry. Every run renders every node again, so to add music, narration or captions to a video an earlier run made, pass its url from get_run outputs to assemble_video (musicPrompt composes a bed) or edit_asset rather than editing the pipeline and running it again.