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/TEMBED_SIGNATURE_MATCHING.md

@@ -23,7 +23,7 @@ We have successfully implemented the **core device identification feature** for
 
 ### Files Found
 
-Location: `/home/dell/coding/giglez/signatures/t-embed-rf/`
+Location: `/path/to/giglez/signatures/t-embed-rf/`
 
 | Filename | Status | Frequency | Samples | Notes |
 |----------|--------|-----------|---------|-------|
@@ -245,7 +245,7 @@ Confidence: 1.0
 ### Step 1: Analyze T-Embed Files (No Database)
 
 ```bash
-cd /home/dell/coding/giglez
+cd /path/to/giglez
 python3 scripts/analyze_tembed_files.py
 ```