v0.2.1 - Enum tolerance baked into the generator

Through v0.2.0, unknown-enum-value tolerance was a separate post-generation step: xenapi.go generated strict, upstream-style hard-erroring enum parsers, then patch_enums.go rewrote convert_gen.go's default cases afterward. That made sense when the fix was first discovered reactively — now that xenapi.go is fully documented and understood (see v0.2.0's documentation pass), there's no reason not to fix it at the source.

convertEnumTypeToGoFuncTemplate now emits the tolerant default case directly. patch_enums.go is removed, along with its step in regenerate.yml — one less moving part in the regeneration pipeline.

No functional change: a full regeneration produces byte-identical output except for the 72 default-case bodies, which are functionally identical to before (same value = EnumType(strValue) fallback, just emitted directly instead of patched in afterward). Verified against a real XCP-ng host.