[Minor] Migrate src/plugins/lua/reputation.lua to lua_shape

[Minor] Migrate src/plugins/lua/reputation.lua to lua_shape

Replace tableshape with lua_shape in reputation plugin (largest).

Changes:
- ts.shape { ... } → T.table({ ... })
- ts.array_of(x) → T.array(x)
- ts.number + ts.string / fn → T.one_of({T.number(), T.transform(T.string(), fn)})
- ts.one_of(a, b) → T.one_of({named variants})
- :is_optional() → :optional()
- Uses lua_redis.enrich_schema for Redis backend
- Added comprehensive documentation to all fields

Schemas:
- generic_selector: selector-based reputation with whitelist/exclusion
- redis backend: prefix, expiry, and time buckets array
- dns backend: simple DNS list configuration