canvas-submit

# canvas-submit Perform one explicitly authorized Canvas mutation after the scan, approval, and draft boundary. This skill is the interactive submit entry point; neither `canvas-scan`, `canvas-execute`, nor a course drafting skill may invoke it on the user's behalf. ## 1. Enforce the later-message boundary Use the raw text of the **current user message**. Never reconstruct authority from an earlier message, quoted text, a plan decision, an overlay, a schedule, or the agent's own recommendation. Pass the complete current message to `src.mutation_approval.parse_mutation_command`. Accept only one whole expression recognized by that parser: - `submit N` or `提交第N项` for one ordinary assignment; - `take quiz N`, `参加测验第N项`, or `做测验第N项` for one first quiz attempt; - `retake quiz N`, `重做测验第N项`, or `重考测验第N项` for one explicitly authorized retake. Outer whitespace may be retained, but no other prose is allowed. Reject `submit all`, `approve all`, `please submit 1`, `submit 1 and 2`, `take quiz 1 now`, hypotheticals, and any command copied from a prior turn. One message authorizes at most one indexed target. Never translate a vague request into an accepted command. Plan approval is not submission authority. `approve 1`, `all`, `do 1`, and a `plan.json` decision may authorize drafting through `canvas-execute`, but they must never mint or substitute for a mutation receipt. This skill is not an automatic-submit or cron workflow. ## 2. Bind the current plan target Use only the run d...