Type generation is manual and error-prone — needs automation

[sameh-farouk]

Problem

The type definitions in src/types/ are hand-maintained. This has led to several issues:

• Stale types: When new chain spec versions are added, type files are manually edited. This is error-prone and has resulted in incorrect or outdated type definitions remaining in the codebase.
• Inconsistent mapping references: Mapping files reference type versions that don't match the generated event hashes, causing silent mismatches (e.g. wrong version aliases like v122 vs v123, missing renames after type changes).
• No version tracking: There is no log of which spec versions have been processed by the type generator. Developers must manually inspect files to determine what's current.
• Multi-file edits required: Adding support for a new chain spec version requires editing multiple type files, the event definitions, and potentially the mapping handlers — all by hand.
• Duplicate type definitions: Without automation, types that should be shared across versions are duplicated, leading to drift.

Impact

• Risk of indexing incorrect data due to type mismatches
• High friction for adding new spec version support
• No reproducibility — different developers may generate slightly different types

Expected Outcome

An automated make typegen workflow that:

• Generates types from chain metadata deterministically
• Maintains an append-only version log for traceability
• Ensures mapping files reference the correct generated type versions