fix: resolve pnpm content-addressable store packages in vxrn patch

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Summary

• pnpm store discovery — applyDependencyPatches now globs .pnpm/<module>@*/node_modules to find packages that only exist in pnpm's content-addressable store (not hoisted to node_modules/ or .pnpm/node_modules/). This fixes silent patch failures in pnpm monorepos with strict hoisting, peer dep conflicts, or hoist=false.
• Real-path deduplication — resolves symlinks before patching to prevent double-patching when node_modules/<module> symlinks and .pnpm/<store>/node_modules/<module> directories point to the same physical files. Critical for non-idempotent transforms like ['jsx'] and ['flow'].
• Zero overhead for non-pnpm — the store scan is gated behind existsSync(.pnpm), so npm/yarn/bun users see no change.

Context

We hit this in a pnpm monorepo (lightstrikelabs/lightstrike-starter#35) where the built-in @react-navigation/core exports patch was silently skipped because the package wasn't hoisted — it only lived at .pnpm/@react-navigation+core@7.16.1_<hash>/node_modules/@react-navigation/core/. The workaround was a manual patchedDependencies entry in package.json. This PR eliminates that workaround by teaching vxrn to discover packages inside pnpm's store.

Changes

packages/vxrn/src/utils/patches.ts:

• Added moduleToPnpmStorePattern() helper (@scope/name → @scope+name)
• Expanded nodeModulesDirs construction to glob pnpm store entries per patch module
• Added patchedRealPaths Set with realpathSync dedup before patch application

packages/vxrn/src/utils/patches.test.ts (new):

• moduleToPnpmStorePattern unit tests (scoped + unscoped)
• pnpm store discovery for non-hoisted packages
• Dedup when symlink + store entry resolve to same files
• Flat node_modules regression (non-pnpm)
• Version constraints across multiple store versions
• Hoisted + store coexistence dedup

Test plan

• All 8 new tests pass (npx vitest run src/utils/patches.test.ts)
• TypeScript type check clean (tsc --noEmit)
• Verify in a pnpm monorepo: remove manual patchedDependencies workaround, run one dev, confirm @react-navigation/core exports patch is applied
• Verify existing non-pnpm examples (one-basic) still work with one patch

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@natew Would appreciate your review on this when you get a chance. This fixes silent patch failures in pnpm monorepos — we hit it in our starter repo and had to work around it with a manual patchedDependencies entry.