fix(attach): replay at attached terminal size

[aksOps]

Summary

• apply attach terminal geometry before initial session replay
• keep same-size repaint nudge PTY-only so replay content is not truncated
• add regression coverage for current-size replay and same-size reattach

Verification

• go test ./... -count=1

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud