[Docs] remove space after Task prefix

[learncold]

Summary

• Remove the space after the Task- prefix in issue templates and repository docs.
• Keep the documented naming rule aligned with existing issue titles updated to Task-....

Related Issue

• None (docs/policy-only PR)

Area

• Engine
• Domain
• Application
• Docs
• Build
• Analysis
• Chore

Architecture Check

• I kept the dependency direction application -> domain -> engine.
• I did not add Qt UI code to src/domain.
• I did not add domain or application dependencies to src/engine.
• I used src/ as the include root.

Verification

• cmake --preset windows-debug
• cmake --build --preset build-debug
• ctest --preset test-debug
• Not run (reason below)

Docs/policy-only change.

Risks / Follow-up

• None.