MAINT-001: Update safe Python dependencies

- Flask 3.1.1 → 3.1.3 (bugfix)
- Werkzeug 3.1.5 → 3.1.8 (bugfix)
- requests 2.32.4 → 2.34.2 (minor feature)
- ccxt 4.5.38 → 4.5.59 (latest in v4.x)
- certifi 2025.7.9 → 2026.6.30 (CA bundle refresh)
- Pandas/numpy skipped (v3 needs testing)

Co-Authored-By: Claude <noreply@anthropic.com>

requirements.txt

@@ -1,10 +1,10 @@
 blinker==1.9.0
-certifi==2025.7.9
+certifi==2026.6.30
 charset-normalizer==3.4.2
 click==8.2.1
-ccxt>=4.5.38,<5
+ccxt>=4.5.59,<5
 colorama==0.4.6
-Flask==3.1.1
+Flask==3.1.3
 idna==3.10
 itsdangerous==2.2.0
 Jinja2==3.1.6
@@ -15,8 +15,8 @@ pandas>=2.2.3,<3
 python-dateutil==2.9.0.post0
 python-dotenv==1.1.1
 pytz==2025.2
-requests==2.32.4
+requests==2.34.2
 six==1.17.0
 tzdata==2025.2
 urllib3==2.6.3
-Werkzeug==3.1.5
+Werkzeug==3.1.8