Fix: robust Nitter URL handling + safe Instagram requests (timeouts, no crash)

[TheDudeXxXx]

Prevents hangs & crashes in Nitter/Instagram lookups by adding scheme validation, timeouts, and graceful failover. Scans now finish even if an endpoint is flaky.

Changes

Twitter/Nitter

• Force https:// scheme if missing
• Add timeouts + try/except
• Skip unreachable instances without stalling

Instagram

• Use requests.Session() with UA header
• Add timeouts
• Gracefully handle exceptions

Testing

Verified:

• No MissingSchema crashes from missing schemes
• Timeouts prevent hangs on unreachable instances
• Instagram lookups run without blocking or throwing UnboundLocalError
• Multiple scans complete cleanly despite flaky endpoints

Impact

• Increased scan stability and speed
• Eliminates manual restarts due to endpoint failures
• No breaking changes — only safer request handling and minor URL validation