MobBridge.kt.eex: MobTextField honours secure: true

[C-Sinclair]

Summary

Companion to GenericJam/mob#12 (mob iOS secure: true for text_field). Wires the Android Compose side so text_field secure={true} actually masks input on both platforms.

In MobBridge.kt.eex's MobTextField composable:

• Read secure: Boolean from the prop bag.
• Apply PasswordVisualTransformation() when set, VisualTransformation.None otherwise.
• When secure: true, override keyboardType to KeyboardType.Password (autocorrect off, no suggestions strip). The override rule documented inline — apps wanting numeric-PIN masking on a Number keyboard can layer their own masking; we can revisit based on real demand.

%{type: :text_field, props: %{
  value: assigns.password,
  placeholder: "Password",
  secure: true,
  on_change: {self(), :password_changed}
}}

Cleartext still reaches the BEAM via on_change — the transformation is purely visual. Existing apps generated from prior templates are unaffected; the prop becomes a no-op there. Regenerating or hand-porting MobBridge.kt enables masking.

CHANGELOG / version

Under ## [Unreleased]. No mix.exs bump — follows the repo's ride-along bump pattern (e.g. 2e566d9 Bump to 0.3.5 — fix three template regressions + add tier-1/3 lint suite rolling up three prior feature commits).

Test plan

• MobNew.Templates.Lint.check_kotlin/1 on the regenerated MobBridge.kt — returns []. All 8 structural checks pass (balanced braces/parens/brackets, no EEx leaks, no duplicate Kotlin imports, etc.).
• mix test — 230/266 pass (same baseline as master; the 36 pre-existing failures are LiveView-path tests requiring mix archive.install hex phx_new, plus the :requires_android_ndk-tagged clang test).
• mix format --check-formatted — clean
• mix credo --strict — clean (129 mods/funs, 0 issues)
• mix compile --warnings-as-errors — clean
• Verified end-to-end in a generated app: tap into a secure: true field, type "hunter2" — Compose renders 7 dots, BEAM-side :password assign holds "hunter2", on-screen length label updates live. Same contract as the iOS verification in text_field: secure: true for masked password input mob#12.

Files

• priv/templates/mob.new/android/app/src/main/java/MobBridge.kt.eex — two new imports (PasswordVisualTransformation, VisualTransformation); isSecure flag in MobTextField; visualTransformation parameter; keyboard-type override
• CHANGELOG.md — entry under ## [Unreleased]

[GenericJam]

Thanks @C-Sinclair — landed as 4a41f47 in mob_new 0.3.8 with your authorship preserved. Paired with mob#12 (iOS SecureField) in mob 0.6.15 so the secure: true contract works across both platforms in the same release.

CHANGELOG entry merged into the [0.3.8] [Unreleased]-renamed section alongside the project_swift_sources hook landing in the same release. Closing since the commit is on master.