GeezerVison

Greptile Summary

This PR adds numeric disambiguation for object properties whose JSON names normalize to the same Go field identifier while preserving their original wire tags.

• Adds a property-level collision-resolution pass in schema generation.
• Adds a unit test for two separator-differing property names.
• The resolved names are not propagated to custom serialization helpers, and the resolver does not reserve the synthetic AdditionalProperties field.

Confidence Score: 3/5

This PR should not merge until collision-resolved names are shared with serialization boilerplate and synthetic struct fields are included in collision handling.

Colliding properties can now compile into structs whose generated marshal/unmarshal methods access the wrong field, while an AdditionalProperties property can still produce an uncompilable duplicate declaration.

Files Needing Attention: pkg/codegen/schema.go and the union/additional-properties boilerplate templates

### Issue 1
pkg/codegen/schema.go:1657-1661
**Boilerplate uses unresolved field names**

When a union or additional-properties object contains properties such as `host-fqdn` and `host_fqdn`, the struct declares the latter as `HostFqdn2`, but generated marshal/unmarshal templates still resolve both accesses as `HostFqdn`, causing the second JSON property to read from or write to the wrong Go field.

### Issue 2
pkg/codegen/schema.go:1779-1784
**Synthetic field collision remains**

When an object allows additional properties and also declares a property named `additionalProperties` or uses `x-go-name: AdditionalProperties`, the resolver does not reserve the synthetic field name, so `GenStructFromSchema` emits two `AdditionalProperties` fields and the generated Go code fails to compile.

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For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

_{Reviews (1): Last reviewed commit: "fix: resolve Go field name collisions wh..." | Re-trigger Greptile}

thanks for the careful review, both points were valid. i reworked the fix so it is a single source of truth instead of only touching the struct declaration:

• collision resolution now runs once per schema (ResolvePropertyGoFieldNameCollisions) and stores the disambiguated name on the property. GoFieldName() returns it, so the struct declaration and the generated marshal/unmarshal boilerplate (union and additional-properties templates, which all read GoFieldName) now use the same name. this fixes the "boilerplate reads the wrong field" case.
• the resolver reserves the synthetic AdditionalProperties field name first, so a real property named additionalProperties (or one using x-go-name: AdditionalProperties) is suffixed instead of producing a duplicate declaration.

added a test for the additional-properties reservation case as well. full pkg/codegen suite and the rest of ./... pass, gofmt and vet clean.