feat: Add Gradio UI apps for AI services

- embeddings.py: BGE embeddings demo with similarity
- stt.py: Whisper speech-to-text demo
- tts.py: XTTS text-to-speech demo
- theme.py: Shared DaviesTechLabs Gradio theme
- K8s deployments for each app

kustomization.yaml

@@ -0,0 +1,9 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+namespace: ai-ml
+
+resources:
+  - embeddings.yaml
+  - tts.yaml
+  - stt.yaml