WRNexusJS v0.6.0 R6 lint corrections

This revision fixes the lint failures reported by bun run check after R5.

Corrected files

editors/vscode/test/formatter.test.js
- Replaced hard-to-count literal regex spaces with quantified spaces.
examples/component-showcase/scripts/generate-showcase.mjs
- Removed unused uiComponentsPath and jsonAttribute declarations.
examples/component-showcase/scripts/showcase-profiles.mjs
- Removed the unused actionSlot declaration.
packages/cli/src/update.ts
- Removed an unnecessary regex escape.
packages/compiler/src/client-codegen.ts
- Rewrote store-path regexes without unnecessary character-class escapes.
packages/compiler/src/codegen.ts
- Rewrote the store-path regex without unnecessary character-class escapes.
packages/syntax/src/diagnostics.ts
- Corrected dynamic RegExp string escaping for word boundaries, property separators, and whitespace.
packages/syntax/src/parser.ts
- Removed an unused FunctionRuntime type import.
patch-overlay-showcase.mjs
- Added explicit Node imports for process and console.
scripts/generate-ui-component-reference.mjs
- Removed an unnecessary closing-parenthesis escape in a regex character class.
scripts/validate-0.6.mjs
- Added explicit Node imports for console, process, and fileURLToPath.
- Replaced URL pathname manipulation with fileURLToPath, improving Windows path handling.

node scripts/validate-0.6.mjs: 14 passes, zero failures; Bun unavailable warning only.
VS Code extension Node tests: 28 passes, zero failures.
VS Code extension validation: all checks passed.
All JavaScript and MJS syntax checks passed.
Exact regression guards for all 31 reported lint findings passed.

Run the complete release gate locally with Bun:

bun install
bun run check