docs: document segment-scoped config globs and extglob groups

[BartWaardenburg]

Summary

This PR documents the glob changes of these fallow PRs:

• fix(discover): keep a single * in entry globs within one segment fallow#3513: a single * in entry and dynamicallyLoaded stays within one path segment.
• fix(config): keep a single * in every config path glob within one segment fallow#3541: the same rule applies to every config path glob.
• fix(graph): match extglob groups in import.meta.glob patterns fallow#3514: import.meta.glob patterns accept the extglob groups @(..), ?(..), +(..), *(..) and !(..).
• fix(graph): apply negative import.meta.glob entries and escape literal pattern text fallow#3537: negative import.meta.glob entries exclude files. Glob characters in the static text of a dynamic import pattern match only themselves.
• refactor: share one extglob rewrite between the graph and the plugins fallow#3544: Storybook, Playwright, Vitest, Rstest and Jasmine globs accept every extglob group.
• fix(extract): read Playwright fixtures from the playwright/test import fallow#3534: Playwright fixtures from playwright/test credit class members. The playwright package with a Playwright config activates the plugin.

Changes

• configuration/overview.mdx: a new "Path globs" section with the rule, examples and the affected fields. Notes on entry, dynamicallyLoaded and ignorePatterns (a .gitignore line can match fewer files). The ignoreFindings text no longer says that * matches /. The overrides example uses **/*.test.ts.
• configuration/boundaries.mdx: a note on * in zone patterns.
• analysis/dead-code.mdx: extglob groups, negative entries and literal text in dynamic import patterns. Playwright fixtures in class member detection.
• frameworks/built-in.mdx: the Playwright activation row, the Storybook extglob line (the old text said that groups other than @(..) match nothing), and a new "Extglob groups in tool globs" section.

Merge order

Merge this PR right after the fallow PRs above, so that the docs parity check stays green. Do not merge it before them.

Checks

npm run check passes.