feat: edit_plan — multi-file edit planning

[kienbui1995]

Multi-file edit planning tool. Agent presents plan before executing changes to 2+ files. 192 tests pass.

Summary by CodeRabbit

New Features

• Added codebase_search tool to search symbols and files by keyword before reading
• Added edit_plan tool to present multi-file edit plans for review before applying changes across multiple files
• Enhanced system prompt with usage guidelines for improved code editing workflows

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 43eddc3a-fae7-4101-9c3e-599ce9ece285

📥 Commits

Reviewing files that changed from the base of the PR and between 91a5b7b and 8d6dda2.

📒 Files selected for processing (4)

• mc/crates/mc-cli/src/main.rs
• mc/crates/mc-core/src/runtime.rs
• mc/crates/mc-tools/src/registry.rs
• mc/crates/mc-tools/src/spec.rs

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📝 Walkthrough

Walkthrough

A new edit_plan tool is introduced across the codebase to enable multi-file edit planning. The tool is integrated into the system prompt, tool registry, runtime dispatch logic, and tool specifications with JSON-based schema for structured edit steps.

Changes

Cohort / File(s)	Summary
System Prompt & CLI mc/crates/mc-cli/src/main.rs	Extended build_system_prompt with two new tool definitions: codebase_search (for pre-read symbol/file lookup) and edit_plan (for multi-file change planning), along with corresponding usage guidelines.
Tool Runtime Dispatch mc/crates/mc-core/src/runtime.rs	Classified edit_plan as a sequential tool; added dispatch handler that parses JSON input expecting a steps array (with optional title), formats and returns a plan summary with confirmation prompt, or returns error if steps is missing/invalid.
Tool Specification & Registry mc/crates/mc-tools/src/spec.rs, mc/crates/mc-tools/src/registry.rs	Added new edit_plan tool specification with JSON schema requiring title (optional) and steps array (each step with required file, action enum, and description); updated registry test assertion to expect 28 tools (increased from 27).

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• feat: address critical gaps — model routing, CI mode, per-tool permissions #27: Modifies tool dispatch logic in mc-core/src/runtime.rs by adding handlers for different tool names, directly related to the new edit_plan dispatch implementation.
• feat: named agents, audit timestamps, --trace logging #32: Updates mc-cli/src/main.rs system prompt construction, shared context with this PR's prompt extensions.
• feat: /diff-preview — approve/reject file changes with diff #15: Changes tool execution classification in mc-core/src/runtime.rs to handle sequential vs. parallel tool processing, relevant to edit_plan's sequential classification.

Poem

🐰 A rabbit hops through code so bright,
With plans to edit left and right!
Now steps align with file and deed,
Multi-tool changes, all we need! ✨

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/edit-plan

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