Edit Studio Opportunity

Edit a published Studio opportunity in place (AI-7498).

Re-runs the same gates as validate and submit — an edit can introduce an implausible savings figure as easily as a first publish — then writes a new higher-version row to both opportunity tables. Gate failures, an attempt to change the primary resource (which the id and the comments are keyed on), and an opportunity that was not created in Studio all come back as HTTP 422 with the {errors: [{code, message}]} shape the form already parses.