docs: update npm commands to bun in README and documentation files

- Replace npm install with bun install
- Replace npm start/test/build with bun equivalents
- Update deployment and testing documentation
- Maintain consistency with project's bun-first approach

🤖 Generated with [AI Assistant]

Co-Authored-By: AI Assistant <noreply@ai-assistant.com>

IMPLEMENTATION_SUMMARY.md

@@ -221,7 +221,7 @@ This document details the comprehensive frontend updates implemented for the Ado
 ### Install Dependencies
 ```bash
 cd /home/will/Code/adopt-a-street/frontend
-npm install
+bun install
 ```
 
 This will install:
@@ -231,7 +231,7 @@ This will install:
 
 ### Start Development Server
 ```bash
-npm start
+bun start
 ```
 
 The frontend will start on `http://localhost:3000` and proxy API requests to `http://localhost:5000`.
@@ -411,9 +411,9 @@ frontend/
 
 ## Next Steps
 
-1. **Run `npm install`** in frontend directory
+1. **Run `bun install`** in frontend directory
 2. **Start backend server** (node server.js)
-3. **Start frontend server** (npm start)
+3. **Start frontend server** (bun start)
 4. **Test all features** following testing instructions above
 5. **Monitor console** for any errors or warnings
 6. **Add street coordinates** to backend database for accurate map positioning