feat(tokens): add zIndex as a global design token

[starboyvarun]

Description

Adds zIndex as a first-class global design token in the Blade token system, resolving TODOs that have been present across Popover, Tooltip, and SpotlightPopoverTour components.

Previously, z-index values lived as hardcoded numbers in utils/componentZIndices.ts with a top-level comment // TODO: Move these properly to tokens at some point. Four component files each had their own // TODO: Tokenize zIndex values comment. This PR resolves all of them.

Changes

• New: packages/blade/src/tokens/global/zIndex.ts — defines semantic z-index layers (hide, base, sticky, overlay, drawer, dropdown, popover) with JSDoc comments, following the same pattern as spacing.ts and motion.ts
• Updated: tokens/global/index.ts — exports the new ZIndex type and zIndex constant alongside all other global tokens
• Updated: tokens/theme/theme.ts — adds zIndex: ZIndex to ThemeTokens, making it overridable via createTheme()
• Updated: tokens/theme/bladeTheme.ts — includes zIndex in the default Blade theme object
• Updated: utils/componentZIndices.ts — removes hardcoded numbers, now reads from the zIndex token (fully backward-compatible; no existing imports need to change)
• Removed 4 resolved // TODO: Tokenize zIndex values comments from Popover.web.tsx, Popover.native.tsx, TourPopover.web.tsx, Tooltip.native.tsx

Additional Information

The values are completely unchanged — this is a pure architectural refactor. All existing component imports of componentZIndices continue to work without any modification.

After this change, consumers who need custom z-index layering (e.g. white-label integrations) can override via createTheme({ zIndex: { popover: 2000 } }).

Component Checklist

• Update Component Status Page — N/A (token-only change, no new component)
• Perform Manual Testing in Other Browsers — N/A (no visual change, values are identical)
• Add KitchenSink Story — N/A
• Add Interaction Tests — N/A
• Add changeset

[changeset-bot]

🦋 Changeset detected

Latest commit: 3021d8e

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@razorpay/blade	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[github-actions]

✅ PR title follows Conventional Commits specification.

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit 3021d8e:

Sandbox	Source
razorpay/blade: basic	Configuration