Tests: GenericReconciler

[iAlexeze]

The GenericReconciler is the core of Orkestra's default reconciler path. It needs
comprehensive unit tests before any community adoption.

[iAlexeze]

Scenarios to cover:

Reconcile with object present in cache — hooks called correctly
Reconcile with object not found — OnNotFound called, no error
Reconcile with deletion timestamp set — handleDeletion called, OnDelete fired
ensureFinalizers — adds missing finalizers, skips if all present
removeFinalizers — removes only Orkestra finalizers, leaves foreign finalizers
Hook type mismatch — panics at startup with clear message
Nil HookFactory — reconciler runs without panicking
Deep copy — mutations inside hooks do not affect the cache
ctx.Err() — returns nil immediately on cancelled context

Test infrastructure needed:

Fake SharedIndexInformer with controllable cache state
Fake Kubeclient with PatchFinalizers stub
Fake Event recorder