fix(filesystem): tolerate quoted, spaced, and 8.3 Windows paths in config args (#447)

[adityachaudhary99]

Closes #447

Paths with spaces, surrounding quotes, a leading tilde, Git-Bash style /c/foo prefixes, or 8.3 short names could fail when configured as allowed directories.

• New parseAllowedDirectories() normalizes every argv entry before validation: trim, strip one pair of surrounding quotes, expand leading ~, win32-only /c/foo to C:\foo conversion, resolve
• Startup symlink resolution switched to realpathSync.native(), which also expands Windows 8.3 short names
• README gains a Windows paths usage subsection

Tests: extended path-utils suite + win32-gated startup spawn tests; green locally on Windows 11.
Note: submitted alongside #470; whichever merges second rebases cleanly (both touch the index.ts startup block).

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