[Important] Controller pattern standardization: reconciliation, create-or-update, deletion

[piwi3910]

Codebase Review Round 2 — Finding #13

Severity: Important
Location: Various controller files

Problem

The codebase uses three different reconciliation patterns, three different create-or-update patterns, and GRPCRoute deletion diverges from other resource types. This inconsistency makes the controllers harder to understand and maintain.

Reconciliation patterns found:

1. Direct reconcile with no generation check
2. Reconcile with generation check but different implementations
3. Reconcile with status update on every run

Create-or-update patterns found:

1. Get → Create/Update with error wrapping
2. Get → Create/Update without error wrapping
3. controllerutil.CreateOrUpdate

Deletion:

• GRPCRoute deletion uses a different pattern from all other resource types

Fix

• Standardize all controllers to use reconcileWithGenerationCheck pattern
• Create a shared reconcileResource helper for the create-or-update pattern
• Standardize deletion to use handleResourceDeletion consistently across all resource types including GRPCRoute