Datascripts: author spell and effect Package Deltas #315

This was generated by AI during triage.

Agent Brief

Category: enhancement
Summary: Add the first typed Datascript API for cloning and changing spells.

Current behavior:
The Package Delta spell tracer accepts artifacts, but authors have no typed API that produces them from base game data.

Desired behavior:
Expose a thin typed authoring API with data.spell(id), cloning to a new identifier, scalar field assignment, and nested SpellEffect access. A read-only base-data snapshot supplies source rows. Datascripts cannot read another Package's generated output. Assignments record exact field claims and emit the canonical Package Delta. Cloning a spell creates and claims its child effects with the packed identifier rule.

Key interfaces:

• Typed spell and SpellEffect authoring objects
• Read-only base-data snapshot
• Package Delta emitter
• lyracore packages build

Acceptance criteria:

• The Fire Nova example clones spell 133, changes fields, loops over five ranks, and emits valid Package Deltas.
• Editor and typecheck use generated schema field names and types.
• Unassigned fields do not become claims on cloned existing rows.
• New spell and child-effect inserts contain every required field.
• Child-effect identifiers follow the packed-key rule.
• Fixture-reserved and non-client-safe identifiers fail during the build.
• A Datascript cannot observe another Package's generated Delta.

Out of scope:

• Other game-data tables
• Applying Package Deltas to a Shard
• Runtime Script authoring