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/SIGNATURE_DATABASE_IMPORT_REPORT.md

@@ -42,7 +42,7 @@ Successfully cloned and analyzed both Flipper Zero and RTL_433 repositories, exp
 git clone https://github.com/flipperdevices/flipperzero-firmware.git
 ```
 
-**Location**: `/home/dell/coding/giglez/signatures/flipperzero-firmware/`
+**Location**: `/path/to/giglez/signatures/flipperzero-firmware/`
 
 ### Signatures Found
 
@@ -100,7 +100,7 @@ git clone https://github.com/flipperdevices/flipperzero-firmware.git
 git clone https://github.com/merbanan/rtl_433.git
 ```
 
-**Location**: `/home/dell/coding/giglez/rtl_433/`
+**Location**: `/path/to/giglez/rtl_433/`
 
 ### Device Protocols Found