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>

.claude/settings.local.json

@@ -0,0 +1,22 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(find:*)",
+      "Bash(cargo check:*)",
+      "Bash(cargo test)",
+      "Bash(cargo test:*)",
+      "Bash(grep:*)",
+      "Bash(cargo install:*)",
+      "Bash(cargo make:*)",
+      "Bash(cargo:*)",
+      "Bash(ls:*)",
+      "Bash(./target/debug/aibot --help)",
+      "Bash(./target/debug/ai --help)",
+      "Bash(mkdir:*)",
+      "Bash(chmod:*)",
+      "Bash(git checkout:*)",
+      "Bash(git add:*)"
+    ],
+    "deny": []
+  }
+}