enhancement: `cortex models delete ...` removes the model but not all metadata around it

[ramonpzg]

When deleting model using cortex models delete ... the metadata.yml and the model's directory will hang around afterwards.

Example

❯ cortex models delete deepseek-r1-distill-qwen-1.5b:1.5b-gguf-q2-k
Model deepseek-r1-distill-qwen-1.5b:1.5b-gguf-q2-k deleted successfully

❯ ls ~/cortexcpp/models/cortex.so/deepseek-r1-distill-qwen-1.5b/1.5b-gguf-q2-k
metadata.yml

❯ bat ~/cortexcpp/models/cortex.so/deepseek-r1-distill-qwen-1.5b/1.5b-gguf-q2-k/metadata.yml
───────┬──────────────────────────────────────────────────────────────────────────────────
       │ File: /home/rpg/cortexcpp/models/cortex.so/deepseek-r1-distill-qwen-1.5b/1.5b-gguf-q2-k/metadata.yml
───────┼──────────────────────────────────────────────────────────────────────────────────
   1   │ version: 1
   2   │ name: deepseek-r1-distill-qwen-1.5b
   3   │ default: 1.5b-gguf-q4-km
───────┴──────────────────────────────────────────────────────────────────────────────────

Adjustment

for the next version, running cortex models delete ... will delete all traces of a mode.

[LeVinhGithub]

Test is passed on Mac/ Window/ Linux