test: add release functional coverage UI tests

[jose-rZM]

Included #80

• A unified Qt Test executable for functional coverage.
• Fixed grammar fixtures organized by category.
• Fixture-list execution for the more general tutor flows.
• Minimal testing hooks guarded by SYNTAXTUTOR_TESTING.
• Helpers for modal dialogs, table dialogs, export flows, and guided wizard flows.
• Input-format flexibility tests for both LL(1) and SLR(1), including:
• extra spaces
• spacing around separators
• tolerant table cell formatting
• Test traceability documentation linking:
• manual test cases
• automated test functions
• fixture groups
• Manual QA scripts updated where the real UI differs from the original conceptual wording

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

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

See analysis details on SonarQube Cloud