Major refactoring: HTTP client unification and project restructuring

## HTTP Client Refactoring
- Create unified HttpClient module (src/http_client.rs)
- Refactor 24 files to use shared HTTP client
- Replace .unwrap() with proper error handling
- Eliminate code duplication in HTTP requests

## Project Restructuring
- Rename package: ai → aibot
- Add dual binary support: aibot (main) + ai (compatibility alias)
- Migrate config directory: ~/.config/ai/ → ~/.config/syui/ai/bot/
- Implement backward compatibility with automatic migration

## Testing Infrastructure
- Add unit tests for HttpClient
- Create test infrastructure with cargo-make
- Add test commands: test, test-quick, test-verbose

## Documentation
- Complete migration guide with step-by-step instructions
- Updated development guide with new structure
- HTTP client API reference documentation
- Comprehensive refactoring summary

## Files Changed
- Modified: 24 source files (HTTP client integration)
- Added: src/http_client.rs, src/alias.rs, src/tests/
- Added: 5 documentation files in docs/
- Added: migration setup script

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Cargo.toml

@@ -1,9 +1,17 @@
 [package]
-name = "ai"
+name = "aibot"
 authors = ["syui"]
 version = "0.1.0"
 edition = "2021"
-description = "latest@2024-08-18"
+description = "ai.bot - Bluesky AT Protocol Bot"
+
+[[bin]]
+name = "aibot"
+path = "src/main.rs"
+
+[[bin]]
+name = "ai"
+path = "src/alias.rs"
 
 [dependencies]
 seahorse = "*"
@@ -19,3 +27,7 @@ rustc-serialize = "*"
 toml = "*"
 iso8601-timestamp = "*"
 sysinfo = "*"
+
+[dev-dependencies]
+mockito = "1.2"
+tokio-test = "0.4"