fix: make tflite native ownership exception-safe

[patrickkabwe]

Previously, createModel() created raw TfLiteModel, TfLiteInterpreterOptions, and TfLiteInterpreter objects manually. The interpreter was later deleted in HybridTfliteModel::~HybridTfliteModel(), while model/options cleanup happened separately in createModel().

That had two issues:

• if an error happened between native allocations, cleanup could be skipped
• delegate-backed interpreters need delegate/native resources to stay alive for the interpreter lifetime, but raw pointer ownership made that lifetime hard to guarantee

This change moves native ownership to RAII wrappers:

• TfLiteModel and TfLiteInterpreterOptions use unique_ptr with TFLite deleters
• TfLiteInterpreter uses shared_ptr with a TFLite deleter
• HybridTfliteModel keeps the shared interpreter owner and uses a non-owning raw pointer only for calls

This makes cleanup deterministic, including when construction or tensor allocation throws.