Add unitPreference to PlatformConfig

[seveibar]

Motivation

• Provide a platform-wide preference for measurement units so consumers can opt into "mm" | "in" | "mil" formatting where applicable.

Description

• Added an optional unitPreference?: "mm" | "in" | "mil" property to the PlatformConfig TypeScript interface in lib/platformConfig.ts.
• Added Zod validation for the new property via unitPreference: z.enum(["mm","in","mil"]).optional() in the platformConfig schema.
• Added tests/platformConfig.unitPreference.test.ts to assert accepted values and to reject unsupported values.
• Regenerated documentation artifacts so the new field appears in README.md and generated/PROPS_OVERVIEW.md.

Testing

• Ran bun test tests/platformConfig.unitPreference.test.ts which passed (2 tests, 0 failures).
• Ran generation scripts bun scripts/generate-component-types.ts, bun scripts/generate-manual-edits-docs.ts, bun scripts/generate-readme-docs.ts, and bun scripts/generate-props-overview.ts which completed successfully.
• Ran typecheck with bunx tsc --noEmit which completed without errors.
• Ran formatting with bun run format which completed successfully.

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Codex Task

[tscircuitbot]

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Thank you for your contribution! 🎉

PR Rating: ⭐⭐
Impact: Minor

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