refactor: Convert to UV Python project with proper package structure

- Restructured project to use src/stocktool package layout
- Migrated to UV for dependency management
- Added pyproject.toml with all dependencies (sv-ttk, pillow, requests, pyyaml)
- Organized test files into tests/ directory
- Updated .gitignore for UV projects
- Comprehensive README with installation and usage instructions
- Removed old unused files (main.py, stock_tool_gui.py, duplicate copy)
- Added CLI entry point: stock-tool command

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.claude/settings.local.json

@@ -0,0 +1,13 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(python -m py_compile:*)",
+      "Bash(python:*)",
+      "Bash(git add:*)",
+      "Bash(uv:*)",
+      "Bash(tree:*)"
+    ],
+    "deny": [],
+    "ask": []
+  }
+}