fix: grant vault deployer access to manage the litellm engine (#84)

## Why
Applying the newly-merged litellm mount (#83) failed at apply time with:

```
Error: failed to write litellm config
URL: PUT https://vault.service.consul:8200/v1/litellm/config
Code: 403. * permission denied
```

The deployer identity (`tf_vault` approle / `woodpecker_terraform_vault` k8s role) can enable the mount via `sys/mounts/admin`, but no policy grants it access to the engine's own data paths, so writing the config and roles is denied.

## Changes
- Add `policies/litellm/admin.yaml` granting `create`/`read`/`update`/`delete` on `litellm/config` and `litellm/roles/*` (plus `read`/`list` on `litellm/roles`), assigned to the same auth roles as the other secret-engine admin policies (`tf_vault`, `woodpecker_terraform_vault`).

## Note
The policy attaches to the deployer's auth roles, so it takes effect on the next token issuance — a re-run of the apply (fresh Vault login) will have the permission and can write `litellm/config` and the roles.

Reviewed-on: #84
Co-authored-by: Ben Vincent <ben@unkin.net>
Co-committed-by: Ben Vincent <ben@unkin.net>

config/litellm_secret_backend_role/litellm/rspamd.yaml

@@ -0,0 +1,10 @@
+---
+models:
+  - claude-haiku-4-5
+  - claude-sonnet-4-6
+max_budget: 50
+ttl: 3600      # seconds (1h)
+max_ttl: 86400 # seconds (24h)
+metadata:
+  team: mailfiltering
+  env: prod

config/litellm_secret_backend_role/litellm/team-a.yaml

@@ -1,11 +0,0 @@
-# Role on the "litellm" mount (directory name = backend mount path).
-# Constrains the virtual keys generated from creds/team-a.
-models:
-  - gpt-4
-  - gpt-3.5-turbo
-max_budget: 50
-ttl: 3600      # seconds (1h)
-max_ttl: 86400 # seconds (24h)
-metadata:
-  team: a
-  env: prod

environments/root.hcl

@@ -36,7 +36,7 @@ terraform {
       version = "2.23.0"
     }
     litellm = {
-      source  = "git.unkin.net/unkin/litellmvaultsecret"
+      source  = "artifactapi.k8s.syd1.au.unkin.net/terraform-unkin/litellmvaultsecret"
       version = "0.1.0"
     }
   }

modules/vault_cluster/modules/litellm_secret_backend/terraform.tf

@@ -6,7 +6,7 @@ terraform {
       version = "5.6.0"
     }
     litellm = {
-      source  = "git.unkin.net/unkin/litellmvaultsecret"
+      source  = "artifactapi.k8s.syd1.au.unkin.net/terraform-unkin/litellmvaultsecret"
       version = "0.1.0"
     }
   }

modules/vault_cluster/modules/litellm_secret_backend_role/terraform.tf

@@ -2,7 +2,7 @@ terraform {
   required_version = ">= 1.10"
   required_providers {
     litellm = {
-      source  = "git.unkin.net/unkin/litellmvaultsecret"
+      source  = "artifactapi.k8s.syd1.au.unkin.net/terraform-unkin/litellmvaultsecret"
       version = "0.1.0"
     }
   }

policies/litellm/admin.yaml

@@ -0,0 +1,26 @@
+# Allow management of the LiteLLM secrets engine (config and roles)
+---
+rules:
+  - path: "litellm/config"
+    capabilities:
+      - create
+      - update
+      - read
+      - delete
+  - path: "litellm/roles/*"
+    capabilities:
+      - create
+      - update
+      - delete
+      - read
+      - list
+  - path: "litellm/roles"
+    capabilities:
+      - read
+      - list
+
+auth:
+  approle:
+    - tf_vault
+  k8s/au/syd1:
+    - woodpecker_terraform_vault