Implement rev-requirements: Generate comprehensive requirements document from codebase analysis

[Copilot]

This PR implements the rev-requirements functionality requested in issue #339, which generates a comprehensive requirements document by reverse-engineering the existing Aplin codebase.

What was implemented

The implementation analyzes the Android application codebase and generates a structured requirements document following the EARS (Easy Approach to Requirements Syntax) notation. The analysis covers:

Core Analysis Areas

• Functional Requirements: 25 requirements extracted from UseCase classes, UI components, and business logic
• Non-functional Requirements: 18 requirements covering performance, security, usability, reliability, maintainability, and operations
• User Stories: 6 comprehensive stories derived from UI flows and user interactions
• Edge Cases: 11 scenarios identified from error handling and validation code
• Acceptance Criteria: Based on existing test suite with 85% confidence rating

Key Features Analyzed

The reverse engineering process identified and documented:

• Application listing and categorization (User apps, Disableable apps, Disabled apps, All apps)
• Search and filtering functionality
• Android system integration (app settings, web search, sharing)
• Google AdMob integration with GDPR compliance
• Clean Architecture implementation with Domain/Data/UI layers
• Comprehensive error handling and edge case management

EARS Notation Implementation

Requirements are properly categorized using EARS syntax:

• SHALL requirements: Standard functional implementations
• WHEN/IF-THEN requirements: Conditional logic from code branches
• WHERE requirements: State-based requirements from UI state management
• MAY requirements: Optional features and preferences
• MUST requirements: System constraints and validation rules

Output

The generated document docs/reverse/Aplin-requirements.md provides:

• System overview and user personas
• Detailed functional requirements with implementation evidence
• Non-functional requirements across all quality attributes
• Edge cases and error scenarios
• Acceptance criteria derived from existing tests
• Analysis confidence metrics and limitations
• Recommendations for additional testing and validation

This reverse-engineered requirements document serves as a comprehensive specification for the existing Aplin application, enabling better understanding of the system's capabilities and facilitating future development and maintenance activities.

---

💬 Share your feedback on Copilot coding agent for the chance to win a $200 gift card! Click here to start the survey.

[Copilot]

Pull Request Overview

This PR implements a comprehensive reverse-engineering solution that analyzes the Aplin Android application codebase to generate a structured requirements document. The implementation examines existing code, test suites, and architectural patterns to extract functional and non-functional requirements using EARS (Easy Approach to Requirements Syntax) notation.

• Analyzes 25 functional requirements from UseCase classes, UI components, and business logic
• Identifies 18 non-functional requirements covering performance, security, usability, and maintainability
• Documents 11 edge cases and error handling scenarios with implementation evidence

[Copilot]

[nitpick] The document title contains Japanese text (要件定義書（逆生成）) which translates to 'Requirements Definition Document (Reverse Generated)'. Consider using English for consistency with the rest of the PR description and codebase documentation.

Suggested change

	# Aplin 要件定義書（逆生成）
	# Aplin Requirements Definition Document (Reverse Generated)

[Copilot]

[nitpick] The user personas section uses Japanese text. For international accessibility and consistency with the codebase, consider translating to English: 'Android device users: Users who want to manage device storage'.

Suggested change

	- **Androidデバイスユーザー**: 端末のストレージを管理したいユーザー
	- **Android device users**: Users who want to manage device storage

[Copilot]

User stories are written in Japanese format. Consider using standard English user story format: 'As an Android device user, I want to...' for better international understanding.

Suggested change

	- **である** Android端末ユーザー **として**
	- **私は** インストールされているアプリケーションの一覧を表示 **をしたい**
	- **そうすることで** 端末にどのようなアプリがインストールされているかを把握できる
	- As an Android device user,
	I want to view a list of installed applications,
	so that I can understand which apps are installed on my device.

[Copilot]

Mixed language usage detected. '51個のKotlinファイルに対するテストコード' should be translated to English: 'Test code for 51 Kotlin files' for consistency.

Suggested change

	- 51個のKotlinファイルに対するテストコード
	- Test code for 51 Kotlin files

[Copilot]

Section header mixes languages: 'Edgeケース' should be either 'Edge Cases' (English) or 'エッジケース' (Japanese) for consistency.

Suggested change

	## Edgeケース
	## エッジケース