fix: fixed rendering sensitive inputs

[gitsad]

What does this PR do?

Fixes sensitive-field rendering in the default form renderer of @mobile-reality/mdma-renderer-react. Fields marked sensitive: true were rendering their values in plaintext while the user typed, only masking pre-filled values — the opposite of the intended behavior. Two accompanying CSS defects made it worse: masked inputs switch to type="password", which had no matching style rule and collapsed to an unstyled native box, and the reveal/mask toggle button wrapped onto its own line below the input instead of sitting inside it.

The bug lived entirely in the shipped default component (not the ag-ui integration example, which just consumes it with no overrides), so it affected every consumer using the default form renderer for sensitive fields.

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing behavior to change)
• Refactor (no functional change)
• Documentation
• CI / tooling

Packages Affected

• @mobile-reality/mdma-spec
• @mobile-reality/mdma-parser
• @mobile-reality/mdma-runtime
• @mobile-reality/mdma-attachables-core
• @mobile-reality/mdma-renderer-react
• @mobile-reality/mdma-prompt-pack
• Blueprint: ___________

Checklist

• I have read the CONTRIBUTING guide.
• My code follows the existing code style (pnpm format and pnpm lint pass).
• I have added or updated tests that cover my changes.
• All tests pass (pnpm test).
• Type-checking passes (pnpm typecheck).
• I have added a changeset (pnpm changeset) if this change affects published packages.
• New or changed MDMA schemas are backwards-compatible (or marked as breaking).
• Sensitive fields are marked with sensitive: true where appropriate.

Screenshots / Examples

Before: typing into a sensitive field showed plaintext (asdasda), and the mask toggle rendered below the input; masked state collapsed the input to a narrow native box.

After: sensitive fields mask from the first keystroke (•••), with the 👁/🔒 toggle overlaid inside a full-width input.