Reset flag state before completion

[M09Ic]

Background

Console completion reuses cobra command trees. Flags parsed by an earlier completion or execution can leave Changed, values, and ArgsLenAtDash state behind, which can influence later completion results for the same command tree.

Approach

• Locate the command being completed from the current input words.
• Reset that command's flag values and Changed state before invoking carapace completion.
• Reset ArgsLenAtDash on the target command and its parents.
• Keep this scoped to the completion path.

Tests

• Added coverage that a previously changed bool flag is restored before completion.
• Added coverage that ArgsLenAtDash is restored after a previous parse containing --.
• Ran go test ./...