Exclude TypeScript and JavaScript from Sonar coverage (#2813)

## Summary

Adds `sonar.coverage.exclusions=**/*.ts,**/*.tsx,**/*.js,**/*.jsx` to
`sonar-project.properties`. There were no existing exclusion entries.

The shared SonarCloud workflow only publishes the Rust lcov report
(`sonar.rust.lcov.reportPaths=lcov.info`). Artcraft's workflow wrapper
does not pass a TypeScript or JavaScript coverage report, so those files
can never appear covered.

That is why [#2805](https://github.com/storytold/artcraft/pull/2805) and
[#2806](https://github.com/storytold/artcraft/pull/2806) fail the
quality gate on **new_coverage** (0.0% against the 80% target) after the
organisation was recreated. They only add `void` in front of existing
TypeScript calls:

- #2805: 53 new lines to cover, all uncovered
- #2806: 38 new lines to cover, all uncovered

[#2807](https://github.com/storytold/artcraft/pull/2807) also touches
TypeScript (`void` in `libs/components`) and is listed here for the same
exclusion, but its current gate failure is duplicated new code (10.6%),
which this PR does not address.

Same approach as
[anicraft#106](https://github.com/storytold/anicraft/pull/106), which
excluded JS, PowerShell and Python for the same reason. filmcraft and
lightcraft already exclude `**/tools/**,**/docs/**,**/examples/**`. This
PR uses extensions because the uncovered TypeScript and JavaScript live
under `frontend/`.

No product code changes. No open PR already edits
`sonar-project.properties`.

## Testing

Visual review of `sonar-project.properties` against anicraft, filmcraft
and lightcraft, and of the shared `sonarcloud.yml` coverage inputs. No
Rust or frontend tests were run (properties file only). The quality-gate
effect on #2805 and #2806 will be visible after this merges and those
branches are updated from main.

- [x] Clean room: no proprietary code, scripts or assets copied
(AGENTS.md)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

<!-- coderabbit-ai-generated:v1 -->

## Summary by CodeRabbit

* **Chores**
* Updated project configuration for coverage reporting. No user-facing
changes.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

sonar-project.properties

@@ -1,2 +1,8 @@
 sonar.projectKey=storytold_artcraft
 sonar.organization=storytold
+
+# CI only publishes the Rust lcov report, so TypeScript and JavaScript never
+# appear covered. Same idea as anicraft excluding JS/PowerShell/Python, and
+# as filmcraft and lightcraft excluding tools/docs/examples.
+sonar.coverage.exclusions=**/*.ts,**/*.tsx,**/*.js,**/*.jsx
+