Reset flag defaults before command execution

[M09Ic]

Background

RunCommandArgs can execute a reused cobra command tree. When the same command instance is reused, flag values and Changed state from an earlier run can leak into later executions that did not pass those flags.

Approach

• Reset the target command's flags after availability checks and before pre-run hooks.
• Restore scalar flag values from DefValue and clear Changed.
• Restore slice flag values from their pflag default representation.

Tests

• Added a regression test that runs the same command object twice.
• The first run passes a bool flag and repeated string-slice values.
• The second run passes no flags and verifies defaults and Changed state are restored.
• Ran go test ./...