feat: use cfg-based coverage exclusion to replace 'ignore-filename-regex' option, setup coveralls & nightly-based coverage

Justfile

@@ -1,9 +1,6 @@
 set shell := ["bash", "-c"]
 set windows-shell := ["powershell.exe", "-NoLogo", "-Command"]
 
-# Regex to exclude files from coverage report, double escapes for Justfile + CLI
-# You can use src/..., but the filename alone is acceptable too
-coverage_exclude_pattern := "src/app\\.rs|audio\\.rs|src/error\\.rs|platform/emscripten\\.rs|bin/.+\\.rs|main\\.rs|platform/desktop\\.rs|platform/tracing_buffer\\.rs|platform/buffered_writer\\.rs|systems/debug\\.rs|systems/profiling\\.rs"
 
 binary_extension := if os() == "windows" { ".exe" } else { "" }
 
@@ -11,39 +8,26 @@ binary_extension := if os() == "windows" { ".exe" } else { "" }
 # !!! --remap-path-prefix prevents the absolute path from being used in the generated report
 
 # Generate HTML report (for humans, source line inspection)
-html: coverage-lcov
+html: coverage
     cargo llvm-cov report \
     --remap-path-prefix \
-    --ignore-filename-regex "{{ coverage_exclude_pattern }}" \
     --html \
     --open
 
 # Display report (for humans)
-report-coverage: coverage-lcov
-    cargo llvm-cov report \
-    --remap-path-prefix \
-    --ignore-filename-regex "{{ coverage_exclude_pattern }}"
+report-coverage: coverage
+    cargo llvm-cov report --remap-path-prefix
 
 # Run & generate LCOV report (as base report)
-coverage-lcov:
-    cargo llvm-cov \
+coverage:
+    cargo +nightly llvm-cov \
     --lcov \
     --remap-path-prefix \
-    --ignore-filename-regex "{{ coverage_exclude_pattern }}" \
+    --workspace \
     --output-path lcov.info \
     --profile coverage \
     --no-fail-fast nextest
 
-# Run & generate Codecov report (for CI)
-coverage-codecov:
-    cargo llvm-cov \
-    --codecov \
-    --remap-path-prefix \
-    --ignore-filename-regex "{{ coverage_exclude_pattern }}" \
-    --output-path codecov.json \
-    --profile coverage \
-    --no-fail-fast nextest
-
 # Profile the project using 'samply'
 samply:
     cargo build --profile profile