feat(tools): implement CRUD operations for thoughts and projects

* Add tools for creating, retrieving, updating, and deleting thoughts.
* Implement project management tools for creating and listing projects.
* Introduce linking functionality between thoughts.
* Add search and recall capabilities for thoughts based on semantic queries.
* Implement statistics and summarization tools for thought analysis.
* Create database migrations for thoughts, projects, and links.
* Add helper functions for UUID parsing and project resolution.

internal/auth/keyring.go

@@ -0,0 +1,29 @@
+package auth
+
+import (
+	"crypto/subtle"
+	"fmt"
+
+	"git.warky.dev/wdevs/amcs/internal/config"
+)
+
+type Keyring struct {
+	keys []config.APIKey
+}
+
+func NewKeyring(keys []config.APIKey) (*Keyring, error) {
+	if len(keys) == 0 {
+		return nil, fmt.Errorf("keyring requires at least one key")
+	}
+
+	return &Keyring{keys: append([]config.APIKey(nil), keys...)}, nil
+}
+
+func (k *Keyring) Lookup(value string) (string, bool) {
+	for _, key := range k.keys {
+		if subtle.ConstantTimeCompare([]byte(key.Value), []byte(value)) == 1 {
+			return key.ID, true
+		}
+	}
+	return "", false
+}