Package Deltas: apply and replay spell claims after base import #309

This was generated by AI during triage.

Agent Brief

Category: enhancement
Summary: Apply validated spell Package Deltas as the final stage of their base import.

Current behavior:
The Spell importer reloads base rows without a Package stage. Existing import metadata stores one current row per Import Family and cannot record Package provenance.

Desired behavior:
After a successful spell base import, apply every enabled spell Package Delta in one validated plan. Record Package, Import Family, artifact hash, source revision, and row counts without overloading the existing base-import stamp. A Package apply is atomic within one Shard and Import Family.

Disabling or removing a Package replays the affected base import and then applies the remaining Package Deltas. It does not restore pre-images. A read-only check prints the exact plan and conflicts without writing.

Key interfaces:

• Spell base-import completion hook
• Package Delta validation and apply plan
• Package import provenance
• Disable and uninstall replay entry point

Acceptance criteria:

• A successful spell import reapplies all enabled spell Package Deltas.
• An invalid or conflicting plan writes no Package rows or provenance.
• One Package apply is atomic within its Shard and Import Family.
• Disabling one Package restores base spell rows and reapplies the remaining Packages.
• Provenance identifies the Package artifact and base-import generation.
• Check mode reports the same plan without changing the Shard.

Out of scope:

• Realm-wide orchestration
• Other Import Families
• Row deletion