Implement Vault secret cache system

New scripts:
- vault-cache.sh: Main cache manager (sync/get/list/status/invalidate)
- vault-env.sh: Sourceable environment with quick accessor functions
- vault-api-cached.sh: Drop-in replacement for vault_api.sh using cache
- nocodb-api.sh: NocoDB API wrapper using cached token
- qdrant-api.sh: Qdrant API wrapper using cached key
- README-vault-cache.md: Documentation

Updated scripts:
- vault_grist_api.sh: Now uses vault cache
- checks/check-memory-table.sh: Uses vault cache
- utils/get-columns.sh: Uses vault cache
- utils/update-type-col.sh: Uses vault cache

Features:
- 29 secrets cached from Vault (6 categories)
- Auto-refresh on stale entries (1hr TTL)
- Vault token cached for 24h
- Restricted permissions (700/600) on cache files
- Fallback to direct Vault API if cache miss

scripts/utils/get-columns.sh

@@ -1,5 +1,18 @@
 #!/bin/bash
-VAULT_TOKEN=*** -sk -X POST -d '{"role_id":"75d2dcfb-9c65-7f60-59b4-eee8c7f8dc0e","secret_id":"6202b465-2f25-547c-ec07-f47cfc4dda3e"}' https://beavault.beawit.net:8200/v1/auth/approle/login)
-TOKEN=*** -r '.auth.client_token')
+# get-columns.sh - List NocoDB columns for a table
+# Uses vault cache for fast token retrieval
 
-curl -sk -H "X-Vault-Token: $TOKEN" https://beavault.beawit.net:8200/v1/kv/data/api/infrastructure | jq -r '.data.data["nocodb-token"]'
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "${SCRIPT_DIR}/../vault-env.sh"
+
+NOCODB_TOKEN=$(vault_nocodb_token)
+TABLE_ID="${1:-mx149yctebfwvys}"
+
+if [ -z "$NOCODB_TOKEN" ]; then
+    echo "Error: Could not retrieve NocoDB token"
+    exit 1
+fi
+
+echo "=== Columns for table ${TABLE_ID} ==="
+curl -s "http://192.168.25.5:8080/api/v2/tables/${TABLE_ID}/columns" \
+  -H "xc-token: ${NOCODB_TOKEN}" | jq -r '.list[] | "\(.id): \(.title) (\(.uidt))"' 2>/dev/null || echo "Failed to get columns"