refactor(deps): restructured codebase to use centralized pi-utils package

- Created new @oh-my-pi/pi-utils workspace package with shared utilities for logging, process management, stream handling, and temporary directory management.
- Migrated all packages to use centralized logger from @oh-my-pi/pi-utils instead of local winston implementations.
- Replaced custom process spawning and stream reading implementations with standardized cspawn and readLines utilities across all modules.
- Converted synchronous file operations and process spawning to async patterns using Bun shell syntax and fs/promises.
- Added streaming edit abort functionality with configurable setting to abort on patch preview failures.
- Updated test framework from vitest to bun:test across all test suites.

packages/coding-agent/package.json

@@ -44,6 +44,7 @@
 		"@oh-my-pi/pi-ai": "workspace:*",
 		"@oh-my-pi/pi-git-tool": "workspace:*",
 		"@oh-my-pi/pi-tui": "workspace:*",
+		"@oh-my-pi/pi-utils": "workspace:*",
 		"@openai/agents": "^0.3.7",
 		"@sinclair/typebox": "^0.34.46",
 		"ajv": "^8.17.1",
@@ -61,8 +62,6 @@
 		"node-html-parser": "^6.1.13",
 		"smol-toml": "^1.6.0",
 		"strip-ansi": "^7.1.2",
-		"winston": "^3.17.0",
-		"winston-daily-rotate-file": "^5.0.0",
 		"zod": "^4.3.5"
 	},
 	"devDependencies": {