Standardize shutdown reasons in gen_server handle_call stop clauses

[oubiwann]

Problem

Different gen_servers use different shutdown reasons, which is inconsistent:

underack.state uses shutdown:

(('stop _from state)
   \`#(stop shutdown ok ,state))

underack.cables uses normal:

(('stop _from state)
   \`#(stop normal ok ,state))

Suggested Fix

Standardize on normal for clean shutdowns (this is the typical OTP convention).

Files

• src/underack/state.lfe
• src/underack/cables.lfe
• Any other gen_servers with stop handlers

Priority

P1 - Consistency issue, not a crash.