security: sanitize personal paths and usernames from documentation

Replaced all instances of:
- /home/dell/coding/giglez → /path/to/giglez
- /home/dell → ~
- leetcrypt → your-username
- PreistlyPython → your-username
- dell@ → user@

Affected files:
- 17 documentation files in docs/
- 2 shell scripts (download_rf_test_datasets.sh, start_web.sh)

No functional changes, only path/username sanitization for privacy.

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

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

docs/PHASE1_COMPLETE.md

@@ -353,7 +353,7 @@ giglez/
 
 #### 1. Database Setup
 ```bash
-cd /home/dell/coding/giglez
+cd /path/to/giglez
 
 # Run setup script
 ./scripts/setup_database.sh
@@ -376,7 +376,7 @@ Expected output: PostGIS version string (3.4+)
 
 #### 3. Python Configuration Test
 ```bash
-cd /home/dell/coding/giglez
+cd /path/to/giglez
 python3 config/database.py
 ```