fix: preserve page titles in navigation actions - #989

Marker 1 is a legitimate Mendix typed-array marker, not an invalid one --
verified in a Marketplace .mpk mxcli has never touched. The note read as
if the navigation lists were corrupt; they were a per-field mismatch with
what Studio Pro writes for those fields.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DufwPkjFimB8BoTm7bWbik

…le override

PR #989 fixed Forms$FormSettings.TitleOverride in the three navigation
writers but shipped without the two artifacts the bug-fix checklist asks
for. This adds them.

mdl-examples/bug-tests/989-navigation-title-override.mdl replays a
navigation profile with a login page, three page menu items (one nested,
to reach the recursive sub-item build), a microflow item and a sub-menu
container -- four Forms$FormSettings, four TitleOverrides.

The evidence in its header is measured, not restated from the PR. A blank
Mendix app's own navigation document already stores TitleOverride = null
on both LoginPageSettings and the home menu item, so the fix is checked
against a Studio Pro-authored document rather than against a warning
count. The control on a real 11.12.0 v2 app, both engines:

  strings -a <nav unit> | grep -c TextTemplate
    4 before the fix (3 page items + the login page), 0 after,
    while grep -c TitleOverride stays at 4 -- the key is still
    written, now as null.

The symptom-table row records the lesson that generalises: grep the
builder's callers before concluding a navigation fix is menu-only. Each
of the three builders is also the profile's login-page builder, so a fix
aimed at menu items alone would have missed half the emitters.

Two things the script makes visible are called out in its header as out
of scope and are not addressed here: describe navigation drops the
`login page` clause (the reader expects a type the document does not
carry), and every list these writers emit uses typed-array marker 1
where the same app's own document has 2 or 3.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DufwPkjFimB8BoTm7bWbik

Marker 1 is a legitimate Mendix typed-array marker, not an invalid one --
verified in a Marketplace .mpk mxcli has never touched. The note read as
if the navigation lists were corrupt; they were a per-field mismatch with
what Studio Pro writes for those fields.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DufwPkjFimB8BoTm7bWbik

…erride-repro

test(navigation): repro script and symptom-table row for the #989 title override