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/types/thought.go

@@ -0,0 +1,57 @@
+package types
+
+import (
+	"time"
+
+	"github.com/google/uuid"
+)
+
+type ThoughtMetadata struct {
+	People         []string `json:"people"`
+	ActionItems    []string `json:"action_items"`
+	DatesMentioned []string `json:"dates_mentioned"`
+	Topics         []string `json:"topics"`
+	Type           string   `json:"type"`
+	Source         string   `json:"source"`
+}
+
+type Thought struct {
+	ID         uuid.UUID       `json:"id"`
+	Content    string          `json:"content"`
+	Embedding  []float32       `json:"embedding,omitempty"`
+	Metadata   ThoughtMetadata `json:"metadata"`
+	ProjectID  *uuid.UUID      `json:"project_id,omitempty"`
+	ArchivedAt *time.Time      `json:"archived_at,omitempty"`
+	CreatedAt  time.Time       `json:"created_at"`
+	UpdatedAt  time.Time       `json:"updated_at"`
+}
+
+type SearchResult struct {
+	ID         uuid.UUID       `json:"id"`
+	Content    string          `json:"content"`
+	Metadata   ThoughtMetadata `json:"metadata"`
+	Similarity float64         `json:"similarity"`
+	CreatedAt  time.Time       `json:"created_at"`
+}
+
+type ListFilter struct {
+	Limit           int
+	Type            string
+	Topic           string
+	Person          string
+	Days            int
+	ProjectID       *uuid.UUID
+	IncludeArchived bool
+}
+
+type ThoughtStats struct {
+	TotalCount int            `json:"total_count"`
+	TypeCounts map[string]int `json:"type_counts"`
+	TopTopics  []KeyCount     `json:"top_topics"`
+	TopPeople  []KeyCount     `json:"top_people"`
+}
+
+type KeyCount struct {
+	Key   string `json:"key"`
+	Count int    `json:"count"`
+}