web-use: add stdlib Browserless helpers

[EdgeClaws]

Summary

• add Browserless /function media-request discovery to web-use
• drop Python requests dependency from Browserless/TinyFish helpers in favor of stdlib urllib
• keep Browserless session output redacted and session files at 0600
• add baseline tests for helper parsing and --help without credentials

Validation

• bash skills/web-use/scripts/test.sh
• python3 skills/web-use/scripts/browserless_session.py --help
• python3 skills/web-use/scripts/tinyfish_browser_extract.py --help
• rg banned local/personal terms in skills/web-use: no matches
• rg requests imports/usages in skills/web-use: no matches

Note: local pre-push gitleaks tripped on an existing historical finding in skills/moltmaster/SKILL.md at commit 8e94f5f, not this diff; staged/current web-use diff scanned clean.

[EdgeClaws]

Follow-up for the gitleaks pre-push note: opened #4 to clean up the Moltmaster false positive. It shortens the current frontmatter description and adds a narrow historical .gitleaksignore fingerprint so full-history gitleaks scans pass without rewriting repo history.