Refactor notebook glob expansion to use filesystem-driven matching

[Achal1607]

Motivation

• Fix brittle hardcoded glob-character detection and incorrect glob expansion so notebook classpath/modulepath relative patterns resolve consistently and expand to concrete file paths before launch.
• Prefer using the real filesystem and PathMatcher rather than manual regex parsing and ad-hoc prefix handling for more robust glob support.

Description

• Replaced character-based glob detection with parsing each entry into a Path and checking filesystem existence in NotebookUtils.expandGlobPaths so existing paths are preserved and non-existing entries are considered for expansion.
• Added expandGlobEntry(String pattern, Path entryPath) which locates the nearest existing ancestor via findExistingRoot and uses FileSystems.getDefault().getPathMatcher("glob:" + pattern) to match candidates under that root.
• Updated NotebookConfigs to call NotebookUtils.expandGlobPaths when building classPath and modulePath so configuration entries are expanded consistently.
• Preserved original entry when parsing fails or when a glob yields no matches and handled invalid paths/missing roots gracefully.

Testing

• Added unit tests NotebookUtilsTest.testExpandGlobPaths to exercise filesystem glob expansion and NotebookConfigsTest.testGlobExpansionForNotebookPaths to validate integration with configuration initialization.
• No automated test suite was executed as part of this change (tests were added but not run).

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Codex Task