feat: add code review functionality and related tests

[Xin9264]

Add a code review module.
Use kimi-cli to review your uncommitted changes or inspect previous commits.

[Copilot]

Pull Request Overview

This PR introduces AI-powered code review functionality to kimi-cli, enabling users to review uncommitted changes or inspect previous commits through an interactive command-line interface.

Key Changes:

• Added a new review meta-command with interactive selection of review targets (uncommitted changes or specific commits)
• Implemented git repository operations for collecting diffs and commit information
• Created comprehensive review guidelines with structured output format for consistent AI-generated feedback

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
src/kimi_cli/tools/review/__init__.py	Core review functionality including git operations, diff collection, and prompt building
src/kimi_cli/tools/review/review.md	Detailed guidelines for AI code review with output schema and formatting rules
src/kimi_cli/ui/shell/metacmd.py	Integration of review command into shell app with user interaction flow
tests/test_review_prompt.py	Unit tests for prompt building and diff truncation

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[Xin9264]

Added a new review tool under the tools directory.
This tool supports bug detection for both uncommitted and committed changes.
Corresponding code review prompts and related test files have also been added or updated.