Add dry-run support to workflow dispatch calls

[miroslavpojer]

Feature Description

Introduce a dry_run input flag on dispatch calls that simulates workflow execution without making any persistent changes. Useful during initial team adoption and developer testing.

Problem / Opportunity

Without a dry-run mode, teams must run workflows in a live environment to verify behaviour. This carries risk during onboarding and makes iterative development harder.

Acceptance Criteria

1. A boolean dry_run input parameter is available on the relevant dispatch workflow(s).
2. When dry_run: true, no changes are applied to any repository or external system.
3. All actions that would have been taken are clearly logged in the workflow output.
4. Existing behaviour is fully preserved when dry_run: false (default).

Proposed Solution

Add a dry_run boolean input to the workflow. Wrap mutating steps with a conditional (if: inputs.dry_run == false) and add a summary logging step for dry-run mode.

Dependencies / Related

No response

Additional Context

No response