Add permissionMode to code-writing agents (#4174)

Add permissionMode to code-writing agents to fix edit behavior

Agents with Write and Edit tools but no permissionMode inherit the
parent's default mode, which requires interactive approval for each
file operation. When running as subprocesses the prompts get
auto-denied, causing agents to create _new.go copies instead of
editing files in place.

Set permissionMode: acceptEdits on all four code-writing agents and
update the golang-code-writer description and prompt to explicitly
prefer editing existing files over creating new ones.

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: JAORMX

.claude/agents/documentation-writer.md

@@ -2,6 +2,7 @@
 name: documentation-writer
 description: Maintains consistent documentation, updates CLI docs, and ensures documentation matches code behavior
 tools: [Read, Write, Edit, Glob, Grep, Bash]
+permissionMode: acceptEdits
 model: inherit
 ---
 

.claude/agents/golang-code-writer.md

@@ -2,6 +2,7 @@
 name: golang-code-writer
 description: Write, generate, or create new Go code — functions, structs, interfaces, methods, or complete packages
 tools: [Read, Write, Edit, Glob, Grep, Bash]
+permissionMode: acceptEdits
 model: inherit
 ---
 
@@ -15,6 +16,15 @@ Invoke when: Writing new Go functions, structs, interfaces, methods, packages, o
 
 Do NOT invoke for: Writing tests (unit-test-writer), reviewing code (code-reviewer), architecture decisions (tech-lead-orchestrator), docs (documentation-writer).
 
+## File Modification Rules
+
+**CRITICAL: Always prefer editing existing files over creating new ones.**
+
+- **Use the Edit tool** to modify existing files in place. NEVER create copies with `_new.go`, `_v2.go`, or similar suffixes.
+- **Use the Write tool** ONLY when creating genuinely new files that don't exist yet.
+- **Read before editing**: Always use the Read tool to examine a file's current content before modifying it.
+- If you need to add a function to an existing package, edit the appropriate existing file — do NOT create a new file unless the change warrants a new file for organizational reasons (e.g., a new logical grouping).
+
 ## ToolHive Code Conventions
 
 Follow Go style, error handling, logging, and testing conventions defined in `.claude/rules/go-style.md`, `.claude/rules/testing.md`, and `.claude/rules/cli-commands.md`. These rules are auto-loaded when touching matching files.

.claude/agents/site-reliability-engineer.md

@@ -2,6 +2,7 @@
 name: site-reliability-engineer
 description: Observability and monitoring guidance — OpenTelemetry instrumentation, metrics, tracing, and monitoring stack configuration
 tools: [Read, Write, Edit, Glob, Grep, Bash]
+permissionMode: acceptEdits
 model: inherit
 ---
 

.claude/agents/unit-test-writer.md

@@ -2,6 +2,7 @@
 name: unit-test-writer
 description: Write comprehensive unit tests for Go code — functions, methods, or components that need thorough test coverage
 tools: [Read, Write, Edit, Glob, Grep, Bash]
+permissionMode: acceptEdits
 model: inherit
 ---