refactor: use positive tone in shell guidance prompts

packages/opencode/src/tool/shell/shell.txt

@@ -2,7 +2,7 @@ Executes a given shell command in a persistent ${shellName} session with optiona
 
 Be aware: OS: ${os}, Shell: ${shell}
 
-All commands run in ${directory} by default. Use the \`workdir\` parameter if you need to run a command in a different directory. AVOID using \`cd <directory> && <command>\` patterns - use \`workdir\` instead.
+All commands run in ${directory} by default. Use the \`workdir\` parameter to run a command in a different directory instead of \`cd <directory> && <command>\` patterns.
 
 IMPORTANT: This tool is for terminal operations like git, npm, docker, etc. DO NOT use it for file operations (reading, writing, editing, searching, finding files) - use the specialized tools for this instead.
 
@@ -28,27 +28,24 @@ Usage notes:
   - The command argument is required.
   - You can specify an optional timeout in milliseconds. If not specified, commands will time out after 120000ms (2 minutes).
   - It is very helpful if you write a clear, concise description of what this command does in 5-10 words.
-  - If the output exceeds ${maxLines} lines or ${maxBytes} bytes, it will be truncated and the full output will be written to a file. You can use Read with offset/limit to read specific sections or Grep to search the full content. Do NOT use \`head\`, \`tail\`, or other truncation commands to limit output; the full output will already be captured to a file for more precise searching.
+  - If the output exceeds ${maxLines} lines or ${maxBytes} bytes, it will be truncated and the full output will be written to a file. Use Read with offset/limit to read specific sections or Grep to search the full content.
 
-  - Avoid using Bash with the \`find\`, \`grep\`, \`cat\`, \`head\`, \`tail\`, \`sed\`, \`awk\`, or \`echo\` commands, unless explicitly instructed or when these commands are truly necessary for the task. Instead, always prefer using the dedicated tools for these commands:
-    - File search: Use Glob (NOT find or ls)
-    - Content search: Use Grep (NOT grep or rg)
-    - Read files: Use Read (NOT cat/head/tail)
-    - Edit files: Use Edit (NOT sed/awk)
-    - Write files: Use Write (NOT echo >/cat <<EOF)
-    - Communication: Output text directly (NOT echo/printf)
+  - Use the dedicated tools for file operations and communication instead of shell commands:
+    - File search: Use Glob
+    - Content search: Use Grep
+    - Read files: Use Read
+    - Edit files: Use Edit
+    - Write files: Use Write
+    - Communication: Output text directly
   - When issuing multiple commands:
     - If the commands are independent and can run in parallel, make multiple tool calls in a single message. For example, if you need to run "git status" and "git diff", send a single message with two tool calls in parallel.
     - If the commands depend on each other and must run sequentially, ${chaining} For instance, if one operation must complete before another starts (like mkdir before cp, Write before Bash for git operations, or git add before git commit), run these operations sequentially instead.
     - Use ';' only when you need to run commands sequentially but don't care if earlier commands fail
     - DO NOT use newlines to separate commands (newlines are ok in quoted strings)
-  - AVOID using \`cd <directory> && <command>\`. Use the \`workdir\` parameter to change directories instead.
-    <good-example>
+  - Use the `workdir` parameter to change directories instead of chaining commands with `cd`.
+    <example>
     Use workdir="/foo/bar" with command: pytest tests
-    </good-example>
-    <bad-example>
-    cd /foo/bar && pytest tests
-    </bad-example>
+    </example>
 
 # Committing changes with git
 
@@ -59,7 +56,7 @@ Git Safety Protocol:
 - NEVER run destructive/irreversible git commands (like push --force, hard reset, etc) unless the user explicitly requests them
 - NEVER skip hooks (--no-verify, --no-gpg-sign, etc) unless the user explicitly requests it
 - NEVER run force push to main/master, warn the user if they request it
-- Avoid git commit --amend. ONLY use --amend when ALL conditions are met:
+- Only use git commit --amend when ALL conditions are met:
   (1) User explicitly requested amend, OR commit SUCCEEDED but pre-commit hook auto-modified files that need including
   (2) HEAD commit was created by you in this conversation (verify: git log -1 --format='%an %ae')
   (3) Commit has NOT been pushed to remote (verify: git status shows "Your branch is ahead")