[varunj-msft]

Description

Part 14 of saving Registry entries across restarts. Stacked on part 13 (#4052); part 15 (#4067) builds on it. This PR's own changes: varunj-msft/PyRIT@varunj-msft/13178-Save-Converters-From-Registry...varunj-msft/13178-Save-Techniques

Design: 4.1 What gets saved, 4.3 What a recipe holds. Where every part fits: PR map.

This is one of the changes for saving Registry entries across restarts. It builds on #4052, which saves converters from the Registry. Until the earlier PRs merge, the diff here also shows their changes.

A technique made with New technique, or through POST /api/techniques, was gone after the backend restarted. It now saves by default and comes back at every start, like saved targets and converters.

• POST /api/techniques takes "persist": true. A saved technique's name follows the saved-name rule (lowercase letters, digits and underscores, starting with a letter, up to 64 characters), or the request gets a 422. Its recipe is the create request without the name, plus who saved it.
• A technique that uses a Temporary converter or adversarial target can't be saved, since those are gone after a restart (typed 400, /errors/not-saveable). Its attack type and attack parameters get the checks restore runs, so a type that can't be saved, a credential, or a Temporary entry named in the parameters is refused the same way. A name another technique has, or a tag that matches a technique's name or another spelling of a tag in use, is a 409 before anything is written, and storage that can't be written is a 503.
• Restore rebuilds a saved technique with the call the API uses, after the converters and targets it names, and keeps who saved it out of the attack's settings. Techniques the startup scripts register are marked From configuration.
• A scan's launch script that registers a technique under a saved technique's name or one of its tags stops the scan, even when the script catches the refusal, so the saved technique can't run in its place.
• GET /api/techniques gives each technique an origin: saved, configuration or temporary.
• The technique editor saves by default. When a converter or adversarial target it uses is Temporary, or the backend refuses those exact settings, the button reads Create as Temporary and a warning says why. A taken name shows on the name field.
• The Techniques table labels each technique Saved, From configuration or Temporary. The backend README and the GUI doc cover saving techniques.

What stays the same: a technique created without persist is Temporary, as before. Settings changed for one run in the Scanner (POST /api/techniques/{name}/edit) are never saved. Startup techniques work as before; they're only labeled From configuration.

Screenshots: New technique saves by default, the saved technique in the Techniques table, and a technique that uses a Temporary converter offered as Temporary with the reason.

Not covered:

• Deleting and changing a saved technique come with FEAT: Delete saved registry entries (part 20) #4071 (part 20) and FEAT: Change saved registry entries through the API (part 21) #4072 (part 21). Until then, delete its file under registry_recipes_source and restart the backend.
• Showing who saved each technique is FEAT: Show who saved each converter, scorer and technique (part 15) #4067 (part 15).