Add test cases that demonstrate the bug where brace expansion fails to match paths containing literal meta characters in directory names.

The following patterns fail to match correctly:
- e/**/{z,other} with e/[x]/[y]/z: brackets interpreted as character class
- f/\{a,b\}/{c,other} with f/{a,b}/c: braces interpreted as brace expansion
- f/\*/{a,other} with f/*/a: asterisk interpreted as wildcard (over-matches)
- f/\?/{a,other} with f/?/a: question mark interpreted as wildcard (over-matches)

These tests will pass once the fix for escaping meta characters in globAlts/buildAlt is implemented.

When processing brace expansion (e.g., `{a,b}`), the globAlts and doGlobAltsWalk functions build new patterns by combining filesystem paths with pattern fragments.
Previously, paths containing meta characters (e.g., `[orderID]`, `{a,b}`, `*`, `?`) were passed directly to buildAlt without escaping, causing them to be interpreted as glob patterns rather than literal path components.

This fix adds an escapeMeta function (the inverse of unescapeMeta) and applies it to filesystem-derived paths before building alternative patterns.

This ensures that:

- `[...]` in paths are not interpreted as character classes
- `{...}` in paths are not interpreted as brace expansions
- `*` and `?` in paths are not interpreted as wildcards

Also renamed metaReplacer to unescapeMetaReplacer for clarity.