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/projects.go

@@ -0,0 +1,90 @@
+package store
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5"
+
+	thoughttypes "git.warky.dev/wdevs/amcs/internal/types"
+)
+
+func (db *DB) CreateProject(ctx context.Context, name, description string) (thoughttypes.Project, error) {
+	row := db.pool.QueryRow(ctx, `
+		insert into projects (name, description)
+		values ($1, $2)
+		returning id, name, description, created_at, last_active_at
+	`, name, description)
+
+	var project thoughttypes.Project
+	if err := row.Scan(&project.ID, &project.Name, &project.Description, &project.CreatedAt, &project.LastActiveAt); err != nil {
+		return thoughttypes.Project{}, fmt.Errorf("create project: %w", err)
+	}
+	return project, nil
+}
+
+func (db *DB) GetProject(ctx context.Context, nameOrID string) (thoughttypes.Project, error) {
+	var row pgx.Row
+	if parsedID, err := uuid.Parse(strings.TrimSpace(nameOrID)); err == nil {
+		row = db.pool.QueryRow(ctx, `
+			select id, name, description, created_at, last_active_at
+			from projects
+			where id = $1
+		`, parsedID)
+	} else {
+		row = db.pool.QueryRow(ctx, `
+			select id, name, description, created_at, last_active_at
+			from projects
+			where name = $1
+		`, strings.TrimSpace(nameOrID))
+	}
+
+	var project thoughttypes.Project
+	if err := row.Scan(&project.ID, &project.Name, &project.Description, &project.CreatedAt, &project.LastActiveAt); err != nil {
+		if err == pgx.ErrNoRows {
+			return thoughttypes.Project{}, err
+		}
+		return thoughttypes.Project{}, fmt.Errorf("get project: %w", err)
+	}
+	return project, nil
+}
+
+func (db *DB) ListProjects(ctx context.Context) ([]thoughttypes.ProjectSummary, error) {
+	rows, err := db.pool.Query(ctx, `
+		select p.id, p.name, p.description, p.created_at, p.last_active_at, count(t.id) as thought_count
+		from projects p
+		left join thoughts t on t.project_id = p.id and t.archived_at is null
+		group by p.id
+		order by p.last_active_at desc, p.created_at desc
+	`)
+	if err != nil {
+		return nil, fmt.Errorf("list projects: %w", err)
+	}
+	defer rows.Close()
+
+	projects := make([]thoughttypes.ProjectSummary, 0)
+	for rows.Next() {
+		var project thoughttypes.ProjectSummary
+		if err := rows.Scan(&project.ID, &project.Name, &project.Description, &project.CreatedAt, &project.LastActiveAt, &project.ThoughtCount); err != nil {
+			return nil, fmt.Errorf("scan project summary: %w", err)
+		}
+		projects = append(projects, project)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("iterate projects: %w", err)
+	}
+	return projects, nil
+}
+
+func (db *DB) TouchProject(ctx context.Context, id uuid.UUID) error {
+	tag, err := db.pool.Exec(ctx, `update projects set last_active_at = now() where id = $1`, id)
+	if err != nil {
+		return fmt.Errorf("touch project: %w", err)
+	}
+	if tag.RowsAffected() == 0 {
+		return pgx.ErrNoRows
+	}
+	return nil
+}