[FEATURE]: Fast failure on network errors and concise error output

Description

Two problems with shell command handling.

Problem A - No short timeout for network ops, no fallback

When the network is flaky (common in China where GitHub HTTPS is often blocked but SSH works fine), the tool sits there for the default 60-120s timeout. No fast failure, no fallback.

Problem B - Error output is way too verbose

When something fails, the tool dumps full stack traces and re-analysis. Every CI cycle is ~5000 tokens of noise.

Proposed Solution

1. Smarter default timeouts: network ops 15s, build 300s, else 30s
2. Quick network probe before API calls
3. Error output: 1-2 line summary, full log to file

Verification

• I have checked that this feature has not been suggested before