feat(api): implement API key management and authentication enhancements

- Added endpoints for managing API keys, including creation, retrieval, updating, and revocation.
- Introduced a new Auth session endpoint to retrieve current tenant and role information.
- Updated the authentication middleware to support API key-based authentication and track last used timestamps.
- Enhanced documentation to reflect new API key functionalities and usage guidelines.
- Improved logging for demo authentication scenarios.

internal/store/memory.go

@@ -43,6 +43,7 @@ type Memory struct {
 	revPrefixes     map[string][]PrefixRow
 	moduleSnapshots map[string]*moduleSnapshotRec
 	asnPrefixCache  map[int64]*ASNPrefixCacheEntry
+	apiKeys         map[string]*apiKeyRec
 
 	// DemoIDs valid after SeedDemo()
 	demoTenantID   string
@@ -57,6 +58,11 @@ type publishedInfo struct {
 	PublishedAt time.Time
 }
 
+type apiKeyRec struct {
+	APIKey
+	TokenHash []byte
+}
+
 type Tenant struct {
 	ID   string
 	Name string
@@ -133,6 +139,7 @@ func NewMemory() *Memory {
 		revPrefixes:       make(map[string][]PrefixRow),
 		moduleSnapshots:   make(map[string]*moduleSnapshotRec),
 		asnPrefixCache:    make(map[int64]*ASNPrefixCacheEntry),
+		apiKeys:           make(map[string]*apiKeyRec),
 	}
 }