Fix Asterisk CLI startup mode compatibility

[ryanmurf]

Summary

• avoid blocking Tokio RwLock reads in local console startup by sharing immutable CLI state directly
• align CLI startup flags with upstream Asterisk 22.0.0 behavior for -x, -r, -s, -f, -c, and -F
• add process-level startup mode tests covering local console, foreground mode, remote execution, socket override, and remote console stdin

Verification

• cargo test -p asterisk-cli --test startup_modes
• cargo test -p asterisk-cli
• cargo build --release -p asterisk-cli
• smoke-tested target/release/asterisk -f -c -g with an isolated config