Archive prepared jobs locally with ZIP fallback

[jamiejk]

Parent

#1

What to build

Persist prepared jobs locally under Patternmaker's ownership. A user-selected archive directory stores collision-safe job folders, while an equivalent ZIP download keeps preparation available when direct folder access is unsupported or denied.

Acceptance criteria

• The user can select and authorize a local archive directory through the browser's supported directory-access capability.
• Each job folder name combines a timestamp, sanitized display-name slug, and short immutable ID.
• Each job folder contains exactly the prepared SVG and companion JSON record.
• A draft package is persisted before any transmission attempt.
• Archived SVG integrity is verified against its recorded SHA-256 checksum.
• The application can list and open valid archived draft and sent jobs from an authorized directory.
• Corrupt or checksum-mismatched jobs remain inspectable but cannot be resent as exact jobs.
• When directory access is unavailable or denied, a ZIP download contains the identical SVG and JSON pair.
• ZIP fallback permits prepare-and-send while warning that durable in-app listing and later status mutation are unavailable without directory access.

Blocked by

• Freeze immutable prepared-job packages #11