fix(docs): standardize C4A-Script tutorial, add CLI identity-based crawling, and add sponsorship CTA

- Switch installs to pip install -r requirements.txt (tutorial and app docs)
- Update local run steps to python server.py and http://localhost:8000
- Set default PORT to 8000; update port-in-use commands and alt port 8001
- Replace unsupported :contains() example with accessible attribute selector
- Update example URLs in tutorial servers to 127.0.0.1:8000
- Add “Identity-based crawling” section with crwl profiles CLI workflow and code usage
- Replace legacy-docs note with sponsorship message in docs/md_v2/index.md
- Minor copy and consistency fixes across pages

docs/examples/c4a_script/tutorial/README.md

@@ -18,7 +18,7 @@ A comprehensive web-based tutorial for learning and experimenting with C4A-Scrip
 
 2. **Install Dependencies**
    ```bash
-   pip install flask
+   pip install -r requirements.txt
    ```
 
 3. **Launch the Server**
@@ -28,7 +28,7 @@ A comprehensive web-based tutorial for learning and experimenting with C4A-Scrip
 
 4. **Open in Browser**
    ```
-   http://localhost:8080
+   http://localhost:8000
    ```
 
 **🌐 Try Online**: [Live Demo](https://docs.crawl4ai.com/c4a-script/demo)
@@ -325,7 +325,7 @@ Powers the recording functionality:
 ### Configuration
 ```python
 # server.py configuration
-PORT = 8080
+PORT = 8000
 DEBUG = True
 THREADED = True
 ```
@@ -343,9 +343,9 @@ THREADED = True
 **Port Already in Use**
 ```bash
 # Kill existing process
-lsof -ti:8080 | xargs kill -9
+lsof -ti:8000 | xargs kill -9
 # Or use different port
-python server.py --port 8081
+python server.py --port 8001
 ```
 
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