fix(cli): handle network errors in version check gracefully

[berettavexee]

Problem

After a successful download, the CLI crashes with a traceback if the GitHub releases API returns a non-JSON response (504 gateway timeout, rate-limit HTML page, etc.):

ContentTypeError: 504, message='Attempt to decode JSON with unexpected mimetype:
text/html; charset=utf-8',
url='https://api.github.com/repos/nathom/streamrip/releases/latest'

Two root causes:

1. aiohttp's resp.json() validates the Content-Type header and raises ContentTypeError on anything other than application/json.
2. The exception propagates uncaught all the way to the top-level CLI handler, crashing the process even though the download itself completed successfully.

Fix

• Pass content_type=None to both resp.json() calls to skip MIME type validation — the response is parsed as JSON regardless, and a JSONDecodeError is caught by the outer try/except below.
• Use gh.get("body") instead of gh["body"] to handle error responses from the GitHub API (rate-limit, 404, etc.) that don't include a body field.
• Wrap the entire function in try/except Exception so any network failure (timeout, DNS, SSL, parse error) is logged at DEBUG level and the check is silently skipped — the version check should never interrupt or crash a download session.

Test plan

• Normal run with working network → update notice shown if newer version exists, nothing shown if up to date
• GitHub API returns 504 → no crash, no notice
• GitHub API rate-limited (returns JSON error object without body) → no crash, no notice
• No network at all → no crash, no notice

🤖 Generated with Claude Code