feat(tooling): JetBrains IDE support, LSP navigation, barrel imports, package scripts and hooks

- JetBrains plugin 1.4.0: semantic colours (builtin / vendor / own), template strings,
  brace handling, run configurations and a test console, package.ludic and
  package.lock.ludic editing (completion, docs, app preview, colour previews, asset
  navigation), External Libraries for the runtime and packages, doc pages for built-ins
- ludic-lsp: go to definition for imports, document links, hover with inferred types,
  type definition, signature help with parameters, docs from docs/language
- `import "dir"` resolves a barrel `dir/index.ludic`
- package.ludic `entry`, `script` and `hook before|after <command>`; `ludic <script>`,
  `ludic script`, `ludic scripts`
- `ludic test --verbose` and `--test NAME`; the test runner filters by name

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

changes/jetbrains-ide.md

@@ -0,0 +1,23 @@
+bump: minor
+type: feat
+The JetBrains plugin covers much more of the IDE:
+- Run configurations for `ludic run`/`build`/`test` (plus any other `ludic` command), with
+  gutter run buttons on `program` and on every `test "name"` block.
+- Test results appear in the IDE's test tree, with navigation back to each test block.
+- `file.ludic:line` locations are clickable in every console.
+- Smart indentation on Enter and when typing a closing bracket; quotes pair up.
+- A Color Scheme page and a Code Style page.
+- Live templates, New Ludic File templates, and a Ludic project in File | New | Project.
+- A Tools | Ludic menu, and a warning when the toolchain is missing.
+- `package.ludic` is treated as a package manifest:
+  - a banner offers Fetch, Update, Verify, Run, Test, Build and Bundle, and warns when the lock is
+    missing or older than the manifest;
+  - gutter actions on `package` and `require` lines;
+  - completion and quick documentation for directives and `app` keys;
+  - its own icon.
+- `script` and `hook` lines complete and are validated; each script has a run button, the
+  package banner has script shortcuts, and Tools | Ludic | Run Script… lists them all.
+- The toolchain's and the project's packages are listed under External Libraries.
+- The Structure view, parameter info and code-block navigation now come from `ludic-lsp`.
+- The plugin is now 1.4.0 and requires IntelliJ Platform 2024.2 or newer and LSP4IJ 0.21.
+- Fixed: Enter no longer inserts an extra `}`, and Comment Line no longer writes two spaces.