test(debug): smoke-test debugging each language's fixture (#1357)

Debugs each language's fixture the way the editor does, against openidea-server and the debugger the IDE installs: a breakpoint on the entry point's marker line, Debug from the file's context, then the paused frame, its variables, Evaluate Expression, Step Over and Resume. Runs per language in the Language smoke workflow. The build model is loaded first, as the Build Tools feature does, so a Gradle Application is debugged through Gradle; Step Over allows a repeated stop on a line (Python 3.12 reports a conditional expression's line twice).

.github/workflows/language-smoke.yml

@@ -3,7 +3,9 @@ name: Language smoke
 # with a quick fix, an intention, formatting, rename) per language, against the language
 # server the app starts by default: crates/ide-host/tests/language_smoke.rs.
 # Then running and testing each fixture through the run store and openidea-server
-# (Run, Run tests, the test tree, Rerun Failed Tests): smoke/run.test.ts.
+# (Run, Run tests, the test tree, Rerun Failed Tests): smoke/run.test.ts; and debugging its
+# entry point with the debugger the IDE installs (breakpoint, frames, variables, evaluate,
+# Step Over, Resume): smoke/debug.test.ts.
 on:
   push:
     branches: [main]
@@ -17,6 +19,7 @@ on:
       - "Cargo.toml"
       - "Cargo.lock"
       - "src/features/run/**"
+      - "src/features/debugger/**"
       - "src/platform/**"
       - "smoke/**"
       - "package.json"
@@ -108,3 +111,6 @@ jobs:
       - run: pnpm install --frozen-lockfile
       - run: cargo build --locked -p ide-host --bin openidea-server
       - run: pnpm smoke smoke/run.test.ts -t "^${{ matrix.language }}$"
+      - run: pnpm smoke smoke/debug.test.ts -t "^${{ matrix.language }}$"
+        # The IDE installs the debugger from GitHub releases: authenticated, against rate limits.
+        env: { GITHUB_TOKEN: "${{ github.token }}" }