Navigation: an undefined glyph kills mxbuild with no error file, a partial create or modify navigation resets the menu #1522

Summary

Navigation: an undefined icon glyph makes mxbuild exit 1 with no error file, a partial create or modify navigation resets the menu, and a home page that a role cannot open is only caught at build. Related, closed: #1008, #1059 (icon kinds), PR #1075 (glyph that broke deploy at 0 errors, MDL078); lint rule MPR007 exists in v0.26.0.

Repro (blank Mendix 11.15 app)

1. create or modify navigation Responsive ( menu item 'A' (page M.P1, icon glyph 57388) ); (57388 is not in the font table).
2. mxcli check prints MDL078 as a warning; exec applies; mxbuild --target=deploy exits 1 ("Sequence contains no matching element") and writes no error file.
3. Run a second create or modify navigation Responsive that lists only a new item: the first item is gone.
4. home page M.P on the default profile for an app whose role cannot open P: CE2729 at build.

Expected

A glyph that is not in the font is an error at check, or at least the gate gets an error file; a partial modify keeps items it does not mention (or the docs say it replaces); a home page unreachable by a role is flagged before the build.

Actual

Warning only; build fails with exit 1 and no error file; the menu is replaced; CE2729 at build.

MDL078 is documented as a deliberate warning because the glyph table is a snapshot, so the open asks are: (a) a failing exec or gate message that names the glyph, (b) partial-modify semantics, (c) an MPR007-style check in check --references.

Tested with: Mendix 11.15.0, mxcli v0.26.0 (the relevant code also read in the v0.27.0 source), macOS. Not retested on v0.27.0.