perf(pluginutils): compile createFilter patterns once

[Cherry]

The matcher returned by getMatcher rebuilt the glob string and compiled a new picomatch matcher inside every test() call. Compile it once when the filter is created instead, and add a test that the number of picomatch compilations does not grow with the number of filter calls.

Rollup Plugin Name: pluginutils

This PR contains:

• bugfix
• feature
• refactor
• documentation
• other

Are tests included?

• yes (bugfixes and features will not be merged without tests)
• no

Breaking Changes?

• yes (breaking changes will not be merged unless absolutely necessary)
• no

If yes, then include "BREAKING CHANGES:" in the first commit message body, followed by a description of what is breaking.

List any relevant issue numbers:

Picks up similar work in #1921, which was closed as abandoned.

Description

Discovered this minor improvement while benchmarking a larger project internally.

createFilter's string matchers rebuilt the glob and compiled a new picomatch matcher inside every test() call, so every filtered id paid the full compile cost for every pattern. This compiles each pattern once when the filter is created.

With a realistic include/exclude pair (src/**/*.ts, src/**/*.vue / src/storybook/**/*, src/**/*.stories.ts) over ~670 real paths, a filter call went from ~22.6µs to ~1.1µs, with identical results for every path.

[greptile-apps]

Confidence Score: 5/5

[Medium risk] Optimizes pattern matching in the filter utility.

The PR appears safe to merge; no outstanding or new actionable findings remain.

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