[Tool] Add ApplyPatchTool - multi-file patch operations

[omatheusmesmo]

Motivation

When performing refactors, renames, or multi-file changes, the agent must make multiple sequential writeFile/fileEdit calls. A patch tool allows atomic-ish multi-file operations in a single tool call.

Two of three reference projects have this as a core tool.

What the tool should do

Apply a structured patch that can add, update, delete, and move files in a single call.

Reference implementations

opencode (TypeScript)

• Custom patch format with Begin Patch / End Patch markers
• Supports: Add File, Update File, Delete File, Move File
• LSP diagnostics for all modified files
• Formatter integration

openclaw (TypeScript)

• OpenAI-style patch envelopes (Begin Patch / End Patch)
• Workspace-only restriction by default
• Sandbox bridge support

hermes-agent (Python)

• V4A patch format support (compatible with Codex, Cline)
• V4A supports: Update File, Add File, Delete File, Move File
• Fuzzy matching within update hunks

Requirements

1. Add new file - Create a file with specified content
2. Update existing file - Apply text replacements (like FileEditTool but within a patch)
3. Delete file - Remove a file
4. Move/rename file - Move from one path to another
5. Workspace confinement - All paths must be within workspace root
6. Diff preview - Return unified diff for each modified file

Suggested location

client/runtime/src/main/java/dev/omatheusmesmo/qlawkus/tool/shell/ApplyPatchTool.java

Config properties

• qlawkus.file.patch.enabled (boolean, default true)