Added editing and coding guidelines.

CLAUDE.md

@@ -10,18 +10,28 @@ I'm an engineer. I know what I want. You must not propose next actions, unless I
 ## Exploration
 
 - You must not use search tools nor commands that scan the whole workstation filesystem, nor significant parts of it.
-- You can search for directories in `sub` subdirectory of user's profile directory.
+- You can search for directories in `src` subdirectory of user's profile directory.
 - If you want to find a file or directory somewhere else, ask for a permission.
 
+## General editing
+
+- Use available edit tools like Read, ReadFile, Edit, EditFile, Write, WriteFile, etc.
+- Don't use Python, scripting languages or command-line tools to edit-create-write content unless asked or given permission.
+
+## Running command line utilities
+
+- Avoid creating single line multiple command invocations. These construct make it harder to configure allowed commands for the session.
+
 ## Coding
 
-- Prefer using standard library functions or modules.
+- Prefer using standard library functions or modules, unless instructed to do otherwise or minimize the size of generated code.
 - Avoid creating single use code fragments like functions, methods, etc.
 - Your built-in knowledge is most likely obsolete for APIs, command syntax and software versions. Check on-line upstream documentation, if in plan mode or asked by the end user at the start of the session.
 - Do not guess nor infere syntax, API, commands and arguments.
 - Do not put reasoning comments into the source code.
 - Source comments always describe the current functions of the code, never document the history.
 - Unusual coding diverging from upstream documentation can be commented after the end-user approval.
+- Design decision go to ADR.md (Architectural Decision Record).
 
 ### Documentation and code comments