Add internal link and package manifest inspection

[erseco]

Summary

• extract internal exe-node:<pageId> references from HTML and structured iDevice state
• add getInternalLinks() and getBrokenInternalLinks()
• expose used and packaged iDevice runtime types
• add getMissingIdeviceRuntimes()
• add a categorized package manifest covering root files, theme, libraries, iDevice runtimes, project resources and other files
• report broken internal links as validation errors
• report missing packaged iDevice runtimes as validation warnings
• include internal links and the package manifest in detailed serialization
• avoid double-counting normalized standard-JSON state

Stack

This PR is stacked on #20 and targets test/upstream-regression-corpus.

Tests

Covers valid/broken internal links, links inside structured state, runtime presence, manifest categorization and validation diagnostics.

CI is green on PHP 8.0–8.5, coverage, Composer validation, PHPCS and PHPStan.