feat: add Citations and WatchlistChat components, integrate with API

- Implemented Citations component to display citation data.
- Created WatchlistDrawer and ChatSidebar components for managing watchlists and AI chat functionality.
- Integrated API calls for watchlist management and chat interactions.
- Updated index.tsx to include new components in the main application layout.
- Added API client in lib/api.ts for structured API interactions.
- Developed Alerts, Dashboard, Portfolio, Routines, Screener, and Report pages with relevant data fetching and UI components.
- Introduced styles in tokens.css for consistent theming across the application.
- Configured TypeScript and Vite for project setup and development.

backend/internal/store/db.go

@@ -0,0 +1,78 @@
+// Package store persists snapshots, derived tables, routines, alerts, reports,
+// the accuracy ledger, and the credit ledger on SQLite (modernc.org/sqlite,
+// pure Go — no CGO so demo machines without gcc still build).
+package store
+
+import (
+	"database/sql"
+	"embed"
+	"fmt"
+	"sort"
+
+	_ "modernc.org/sqlite"
+)
+
+//go:embed migrations/*.sql
+var migrationsFS embed.FS
+
+// DB wraps database/sql with FlowSight helpers.
+type DB struct {
+	*sql.DB
+	Path string
+}
+
+// Open connects to path (created if missing) and applies numbered migrations.
+func Open(path string) (*DB, error) {
+	sqldb, err := sql.Open("sqlite", path)
+	if err != nil {
+		return nil, fmt.Errorf("store: open %s: %w", path, err)
+	}
+	sqldb.SetMaxOpenConns(1)
+	db := &DB{DB: sqldb, Path: path}
+	if err := db.migrate(); err != nil {
+		sqldb.Close()
+		return nil, err
+	}
+	return db, nil
+}
+
+func (db *DB) migrate() error {
+	entries, err := migrationsFS.ReadDir("migrations")
+	if err != nil {
+		return err
+	}
+	var names []string
+	for _, e := range entries {
+		if !e.IsDir() {
+			names = append(names, "migrations/"+e.Name())
+		}
+	}
+	sort.Strings(names)
+	for _, n := range names {
+		b, err := migrationsFS.ReadFile(n)
+		if err != nil {
+			return err
+		}
+		if _, err := db.Exec(string(b)); err != nil {
+			return fmt.Errorf("store: migration %s: %w", n, err)
+		}
+	}
+	return nil
+}
+
+// Meta helpers persist incremental cursors (quarterly_since, news_since,
+// filings_since) and dedup markers so restarts resume incrementally.
+
+// GetMeta returns a meta value or "".
+func (db *DB) GetMeta(key string) string {
+	var v string
+	_ = db.QueryRow(`SELECT value FROM meta WHERE key=?`, key).Scan(&v)
+	return v
+}
+
+// SetMeta upserts a meta value.
+func (db *DB) SetMeta(key, value string) error {
+	_, err := db.Exec(`INSERT INTO meta(key,value) VALUES(?,?)
+		ON CONFLICT(key) DO UPDATE SET value=excluded.value`, key, value)
+	return err
+}