test(glob-import): cover array patterns with sibling dirs sharing a prefix

[shulaoda]

Summary

• Adds a playground test case covering import.meta.glob([...]) where the array entries target sibling directories whose names share a byte-level prefix but are distinct path segments (e.g. pattern1/ and pattern2/).
• The fixture creates playground/glob-import/array-common-base/pattern{1,2}/*.js, wires up a new array-common-base-result block in index.html, and asserts the resolved modules in glob-import.spec.ts (runs in both serve and build modes).
• Regression guard for vitejs/vite#22170, fixed upstream in rolldown/rolldown#9070.

Why

During vite build, array import.meta.glob patterns are handled by rolldown's native viteImportGlobPlugin. Its get_common_base used a byte-wise longest common prefix to decide where to start walkdir. For array entries like /array-common-base/pattern1/**/*.js and /array-common-base/pattern2/**/*.js, that produced /array-common-base/pattern — a path that cuts in the middle of a segment and points to no real directory. walkdir then found nothing and the bundled output was Object.assign({}). Dev (vite dev) took a different code path and worked fine, so the regression only surfaced in production builds.

rolldown/rolldown#9070 fixed get_common_base to always land on a path-segment boundary. This test pins that behavior on the Vite side so a future regression is caught by the playground e2e suite rather than by users.