feat: major restructuring in migration to terragrunt

- migrate from individual terraform files to config-driven terragrunt module structure
- add vault_cluster module with config discovery system
- replace individual .tf files with centralized config.hcl
- restructure auth and secret backends as configurable modules
- move auth roles and secret backends to yaml-based configuration
- convert policies from .hcl to .yaml format, add rules/auth definition
- add pre-commit hooks for yaml formatting and file cleanup
- add terragrunt cache to gitignore
- update makefile with terragrunt commands and format target

policies/sshca/roles/admin.yaml

@@ -0,0 +1,14 @@
+# Allow administration of SSH CA roles
+---
+rules:
+  - path: "sshca/roles/*"
+    capabilities:
+      - create
+      - update
+      - read
+      - delete
+      - list
+
+auth:
+  approle:
+    - tf_vault

policies/sshca/sign/host.yaml

@@ -0,0 +1,11 @@
+# Allow signing SSH host certificates
+---
+rules:
+  - path: "sshca/sign/host"
+    capabilities:
+      - create
+      - update
+
+auth:
+  approle:
+    - sshsigner

policies/sshca/sign/user.yaml

@@ -0,0 +1,11 @@
+# Allow signing SSH user certificates
+---
+rules:
+  - path: "sshca/sign/user"
+    capabilities:
+      - create
+      - update
+
+auth:
+  approle:
+    - sshsigner

policies/sshca/sshca_roles_admin.hcl

@@ -1,3 +0,0 @@
-path "sshca/roles/*" {
-  capabilities = ["create", "update", "read", "delete", "list"]
-}

policies/sshca/sshca_signhost.hcl

@@ -1,3 +0,0 @@
-path "sshca/sign/host" {
-  capabilities = ["create", "update"]
-}

policies/sshca/sshca_signuser.hcl

@@ -1,3 +0,0 @@
-path "sshca/sign/user" {
-    capabilities = ["create", "update"]
-}