sec: hash tokens in DB, set Tauri CSP, escape quotes in XSS guard

- Session and email verification/reset tokens stored as SHA-256 hash in DB
  (raw token stays client-side in cookie/email link)
- Tauri CSP set: default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline';
  img-src 'self' data: https:; connect-src 'self' wss: https:
- escapeHtml now handles double and single quotes to prevent attribute-based XSS

internal/auth/email_handlers.go

@@ -30,10 +30,11 @@ func (h *Handler) RequestVerification(w http.ResponseWriter, r *http.Request) {
 	}
 
 	token := generateToken()
+	tokenHash := hashToken(token)
 	_, err = h.db.ExecContext(r.Context(), `
 		INSERT INTO user_tokens (user_id, token, type, expires_at)
 		VALUES ($1, $2, 'verify_email', NOW() + INTERVAL '24 hours')
-	`, userID, token)
+	`, userID, tokenHash)
 	if err != nil {
 		http.Error(w, `{"error":"failed to generate token"}`, http.StatusInternalServerError)
 		return
@@ -63,7 +64,7 @@ func (h *Handler) VerifyEmail(w http.ResponseWriter, r *http.Request) {
 		DELETE FROM user_tokens
 		WHERE token = $1 AND type = 'verify_email' AND expires_at > NOW()
 		RETURNING user_id
-	`, req.Token).Scan(&userID)
+	`, hashToken(req.Token)).Scan(&userID)
 	if err != nil {
 		http.Error(w, `{"error":"invalid or expired token"}`, http.StatusBadRequest)
 		return
@@ -100,10 +101,11 @@ func (h *Handler) RequestPasswordReset(w http.ResponseWriter, r *http.Request) {
 	}
 
 	token := generateToken()
+	tokenHash := hashToken(token)
 	_, err = h.db.ExecContext(r.Context(), `
 		INSERT INTO user_tokens (user_id, token, type, expires_at)
 		VALUES ($1, $2, 'reset_password', NOW() + INTERVAL '1 hour')
-	`, userID, token)
+	`, userID, tokenHash)
 	if err != nil {
 		http.Error(w, `{"error":"failed to generate token"}`, http.StatusInternalServerError)
 		return
@@ -134,7 +136,7 @@ func (h *Handler) ResetPassword(w http.ResponseWriter, r *http.Request) {
 		DELETE FROM user_tokens
 		WHERE token = $1 AND type = 'reset_password' AND expires_at > NOW()
 		RETURNING user_id
-	`, req.Token).Scan(&userID)
+	`, hashToken(req.Token)).Scan(&userID)
 	if err != nil {
 		http.Error(w, `{"error":"invalid or expired token"}`, http.StatusBadRequest)
 		return

internal/auth/session.go

@@ -3,6 +3,7 @@ package auth
 import (
 	"context"
 	"crypto/rand"
+	"crypto/sha256"
 	"database/sql"
 	"encoding/hex"
 	"fmt"
@@ -20,17 +21,25 @@ func NewSessionStore(db *sql.DB, cfg *config.Config) *SessionStore {
 	return &SessionStore{db: db, cfg: cfg}
 }
 
+// hashToken computes a SHA-256 hash of a token string.
+// Tokens are stored hashed in the DB so a DB leak doesn't expose active sessions.
+func hashToken(token string) string {
+	h := sha256.Sum256([]byte(token))
+	return hex.EncodeToString(h[:])
+}
+
 func (s *SessionStore) Create(ctx context.Context, userID string) (string, error) {
 	b := make([]byte, 32)
 	if _, err := rand.Read(b); err != nil {
 		return "", fmt.Errorf("generate token: %w", err)
 	}
 	token := hex.EncodeToString(b)
+	tokenHash := hashToken(token)
 
 	_, err := s.db.ExecContext(ctx, `
 		INSERT INTO sessions (user_id, token, expires_at)
 		VALUES ($1, $2, $3)
-	`, userID, token, time.Now().Add(s.cfg.Session.Duration))
+	`, userID, tokenHash, time.Now().Add(s.cfg.Session.Duration))
 	if err != nil {
 		return "", fmt.Errorf("insert session: %w", err)
 	}
@@ -43,7 +52,7 @@ func (s *SessionStore) GetUserIDByToken(ctx context.Context, token string) (stri
 	err := s.db.QueryRowContext(ctx, `
 		SELECT user_id FROM sessions
 		WHERE token = $1 AND expires_at > NOW()
-	`, token).Scan(&userID)
+	`, hashToken(token)).Scan(&userID)
 	if err != nil {
 		return "", err
 	}
@@ -51,6 +60,6 @@ func (s *SessionStore) GetUserIDByToken(ctx context.Context, token string) (stri
 }
 
 func (s *SessionStore) Delete(ctx context.Context, token string) error {
-	_, err := s.db.ExecContext(ctx, `DELETE FROM sessions WHERE token = $1`, token)
+	_, err := s.db.ExecContext(ctx, `DELETE FROM sessions WHERE token = $1`, hashToken(token))
 	return err
 }

web/src-tauri/tauri.conf.json

@@ -23,7 +23,7 @@
       }
     ],
     "security": {
-      "csp": null
+      "csp": "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; connect-src 'self' wss: https:;"
     }
   },
   "bundle": {

web/src/components/MessageInput.tsx

@@ -155,7 +155,7 @@ function markdownToHtml(md: string): string {
 }
 
 function escapeHtml(s: string): string {
-  return s.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
+  return s.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;").replace(/"/g, "&quot;").replace(/'/g, "&#039;");
 }
 
 function inlineMarkdownToHtml(text: string): string {