Sequential execution gets an upgrade: now it's a deliberate choice

Test Cases already ran alphabetically if you dialed parallelism down to 1. We upgraded that into a real mode: an explicit Sequential option with its own say in what happens when something fails.

• One click in the Execute modal: pick Sequential instead of Parallel for any Test Set, Test Case selection, or group of Test Sets.
• Predictable order: Test Cases run one at a time, alphabetically by name, so a step named 01_Login always runs before 02_Create_Report.
• Continue or stop on failure: choose whether the run continues through every Test Case for the full picture, or stops at the first failure and skips the rest.
• Same rule at every level: run multiple Test Sets sequentially, and each set's own cases run in order underneath.

Use it for dependency chains like Create, Edit, Delete, where each step needs the last one's result. Prefix Test Case names with numbers (01_, 02_, 03_) to pin the exact order, and pick Stop when a failed step leaves nothing left to test.

#Sprint28