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/store/links.go

@@ -0,0 +1,69 @@
+package store
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+
+	"github.com/google/uuid"
+
+	thoughttypes "git.warky.dev/wdevs/amcs/internal/types"
+)
+
+func (db *DB) InsertLink(ctx context.Context, link thoughttypes.ThoughtLink) error {
+	_, err := db.pool.Exec(ctx, `
+		insert into thought_links (from_id, to_id, relation)
+		values ($1, $2, $3)
+	`, link.FromID, link.ToID, link.Relation)
+	if err != nil {
+		return fmt.Errorf("insert link: %w", err)
+	}
+	return nil
+}
+
+func (db *DB) LinkedThoughts(ctx context.Context, thoughtID uuid.UUID) ([]thoughttypes.LinkedThought, error) {
+	rows, err := db.pool.Query(ctx, `
+		select t.id, t.content, t.metadata, t.project_id, t.archived_at, t.created_at, t.updated_at, l.relation, 'outgoing' as direction, l.created_at
+		from thought_links l
+		join thoughts t on t.id = l.to_id
+		where l.from_id = $1
+		union all
+		select t.id, t.content, t.metadata, t.project_id, t.archived_at, t.created_at, t.updated_at, l.relation, 'incoming' as direction, l.created_at
+		from thought_links l
+		join thoughts t on t.id = l.from_id
+		where l.to_id = $1
+		order by created_at desc
+	`, thoughtID)
+	if err != nil {
+		return nil, fmt.Errorf("query linked thoughts: %w", err)
+	}
+	defer rows.Close()
+
+	links := make([]thoughttypes.LinkedThought, 0)
+	for rows.Next() {
+		var linked thoughttypes.LinkedThought
+		var metadataBytes []byte
+		if err := rows.Scan(
+			&linked.Thought.ID,
+			&linked.Thought.Content,
+			&metadataBytes,
+			&linked.Thought.ProjectID,
+			&linked.Thought.ArchivedAt,
+			&linked.Thought.CreatedAt,
+			&linked.Thought.UpdatedAt,
+			&linked.Relation,
+			&linked.Direction,
+			&linked.CreatedAt,
+		); err != nil {
+			return nil, fmt.Errorf("scan linked thought: %w", err)
+		}
+		if err := json.Unmarshal(metadataBytes, &linked.Thought.Metadata); err != nil {
+			return nil, fmt.Errorf("decode linked thought metadata: %w", err)
+		}
+		links = append(links, linked)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("iterate linked thoughts: %w", err)
+	}
+	return links, nil
+}