Sync requirements.txt version constraints with pyproject.toml

All packages now have the same minimum version bounds as
pyproject.toml. The most important one is yfinance>=0.2.63 which
fixes the Yahoo Finance API fetch failures that users hit with
older versions.

Fixes #417

requirements.txt

@@ -1,21 +1,21 @@
-typing-extensions
-langchain-core
-langchain-openai
-langchain-experimental
-pandas
-yfinance
-stockstats
-langgraph
-rank-bm25
-setuptools
-backtrader
-parsel
-requests
-tqdm
-pytz
-redis
-rich
-typer
-questionary
-langchain_anthropic
-langchain-google-genai
+typing-extensions>=4.14.0
+langchain-core>=0.3.81
+langchain-openai>=0.3.23
+langchain-experimental>=0.3.4
+pandas>=2.3.0
+yfinance>=0.2.63
+stockstats>=0.6.5
+langgraph>=0.4.8
+rank-bm25>=0.2.2
+setuptools>=80.9.0
+backtrader>=1.9.78.123
+parsel>=1.10.0
+requests>=2.32.4
+tqdm>=4.67.1
+pytz>=2025.2
+redis>=6.2.0
+rich>=14.0.0
+typer>=0.21.0
+questionary>=2.1.0
+langchain_anthropic>=0.3.15
+langchain-google-genai>=2.1.5