refactor: migrate renderer utilities to TypeScript modules

[nihmadev]

assets/js/lib.js combined unrelated concerns in a 1,000-line browser module: text and encoding helpers, DOM behavior, Electron adapters, bug/history state, runtime diagnostics, sandbox execution, UI classes, registry initialization, and legacy globals. Because the renderer loads native ESM directly from disk, this could not be replaced with a TypeScript file without also preserving the emitted .js URLs consumed by the application.

Source and build layout

• Adds assets/ts/lib.ts as the compatibility entry point and assets/ts/lib/* as the typed source modules.
• Adds tsconfig.renderer.json for strict browser ESM compilation with DOM libraries.
• Emits JavaScript and declarations into assets/js, preserving the paths already used by renderer imports.
• Extends npm run build with the renderer TypeScript project and adds npm run build:renderer for focused work.
• Keeps generated .js and .d.ts files in the repository because packaged and development builds load renderer modules directly from assets/js without a bundler or runtime TypeScript loader.

Module boundaries

• text: escaping, capitalization, initials, truncation, linkification, camel-case splitting, and dedent.
• encoding: UTF-8 base64 conversion and DOM identifier encoding.
• format: editor mode lookup, Unix date formatting, path normalization, time conversion, and color alpha conversion.
• values: runtime value classification and the existing object/array predicates.
• dom: tab labels, status transitions, popup behavior, scrolling, generated avatars, CSS variable discovery, code-window visibility, tag replacement, and editor sizing.
• platform: notifications, theme access, clipboard, Twemoji, application title, and GitHub token access.
• history: adapters for the existing global history and bug stores.
• runtimeErrors: runtime error state and bottom-window rendering.
• sandbox: captured console execution and parser/runtime checks.
• ui: reload notification behavior.
• validation: the value validation contract used by notifications without importing the modal engine.

Compatibility retained

The generated assets/js/lib.js remains the public compatibility facade. Existing consumers do not need import changes.

• All 65 named exports are retained with the same names.
• The historical capitilize spelling remains available.
• Existing false, null, and undefined sentinel behavior is preserved where consumers rely on it.
• window.Notificator, window.addToBug, window.addToHistory, window.showIndicator, and window.animate are still assigned.
• Image and font language registration still runs when the facade loads.
• Input focus-state initialization still runs at module evaluation time.
• Class exports retain identity with their existing _ClassName implementations.

Dependency graph changes

Three classes previously imported the compatibility facade that imported those same classes, creating circular module graphs:

• EditorAdapter now imports the language registry directly.
• Options now imports transparentColor from lib/format.js.
• TopBarElement now imports idify from lib/encoding.js.

createNotify now uses the leaf validation module instead of importing modalsHandler/engine.js. Importing notification utilities therefore no longer initializes the modal backdrop and the complete modal component graph.

The debugger window also receives an explicit module-scoped debuggerWindow reference instead of assigning an undeclared global.

Types and documentation

The renderer project is compiled with strict: true. Browser globals that are provided by preload scripts or external scripts are declared in assets/ts/globals.d.ts. Public utility behavior is documented with focused TSDoc comments rather than repeating function names or implementation details.

Verification

• npm run build
• npm test (6/6 tests pass)
• Automated comparison of the old and new facade: all 65 exports match
• Characterization coverage for HTML escaping, capitalization, initials, truncation, dedent, UTF-8 base64, identifier encoding, editor mode lookup, path normalization, time conversion, color conversion, JSON classification, and legacy null behavior
• Confirmed that libClasses no longer import lib.js
• Confirmed that the existing sidebar behavior fix is not included in this PR