feat: add cross-provider --thinking flag mapping to Anthropic/OpenAI

CHANGES
- Add --thinking flag to set reasoning level cross-vendors
- Map Anthropic thinking levels and token budgets appropriately
- Translate OpenAI reasoning effort from thinking levels
- Propagate Thinking through ChatOptions, server, and dry-run output
- Update zsh, bash, fish completions with thinking choices
- Expand suggest_pattern docs with categories, workflows, usage examples
- Remove outdated suggest_pattern user files to avoid duplication
- Add VSCode dictionary terms: Anki, DMARC, wireframes
- Extend tests to include Thinking defaults in ChatOptions

README.md

@@ -576,6 +576,8 @@ Application Options:
       --notification-command=       Custom command to run for notifications (overrides built-in
                                     notifications)
       --yt-dlp-args=                Additional arguments to pass to yt-dlp (e.g. '--cookies-from-browser brave')
+      --thinking=                   Set reasoning/thinking level (e.g., off, low, medium,
+                                    high, or numeric tokens for Anthropic)
 
 Help Options:
   -h, --help                        Show this help message