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/checks/check-memory-table.sh

@@ -1,15 +1,17 @@
 #!/bin/bash
-# Get vault token
-VAULT_RESP=$(curl -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")
+# check-memory-table.sh - Test NocoDB memory table access
+# Uses vault cache for fast token retrieval
 
-VAULT_TOKEN=$(echo "$VAULT_RESP" | jq -r '.auth.client_token')
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "${SCRIPT_DIR}/../vault-env.sh"
 
-# Get nocodb token
-NOCODB_TOKEN=$(curl -sk -H "X-Vault-Token: $VAULT_TOKEN" \
-  "https://beavault.beawit.net:8200/v1/kv/data/api/infrastructure" | \
-  jq -r '.data.data["nocodb-token"]')
+NOCODB_TOKEN=$(vault_nocodb_token)
+
+if [ -z "$NOCODB_TOKEN" ]; then
+    echo "Error: Could not retrieve NocoDB token from vault cache"
+    echo "Run: ${SCRIPT_DIR}/../vault-cache.sh sync"
+    exit 1
+fi
 
 echo "Token: ${NOCODB_TOKEN:0:20}..."