feat: add conflict resolution, linter validation, and SEARCH/REPLACE system

- Add git-style conflict resolution with visual diff highlighting
- Add buffer-local keymaps: co/ct/cb/cn for conflict resolution
- Add floating menu with auto-show after code injection
- Add linter validation that auto-checks LSP diagnostics after accepting code
- Add SEARCH/REPLACE block parsing with fuzzy matching
- Add new commands: CoderConflictMenu, CoderLintCheck, CoderLintFix
- Update README with complete keymaps reference and issue reporting guide
- Update CHANGELOG and llms.txt with full documentation
- Clean up code comments and documentation

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

doc/codetyper.txt

@@ -120,7 +120,7 @@ Default configuration: >lua
 5. LLM PROVIDERS                                      *codetyper-providers*
 
                                                     *codetyper-claude*
-Claude (Anthropic)~
+Claude~
 Best for complex reasoning and code generation.
 >lua
   llm = {