feat: add safe state construction

[SandroMaglione]

Summary

• add .from(...) to initial, full, local, branch, compound, parallel, final, and local.with state builders
• accept each selected schema's exact constructor input and resolve it through schema.makeEffect during planning
• keep construction results opaque until planning succeeds, preserving defaults and TaggedClass identity while reporting validation failures as MachineSchemaDecodeError
• document the decoded-value and constructor-input forms and add runtime plus negative type coverage

Release

Includes a minor Changesets entry. After this PR merges into main, the existing Changesets release PR #6 will incorporate this API together with the changes already queued for that release.

Validation

• pnpm check
• 203 runtime tests
• 91 type tests / 360 assertions
• strict packed-consumer validation
• package verification