contract 0.18.0: one name per display role, the kiosk's own

Core called the roles dashboard / lobby / partskiosk. The kiosks call them
Dashboard / Lobby / 3DPrintRoom, which are the literal contents of
C:\Enrollment\display-type.txt, read by the GE-Enforce dispatcher to pick a
target. Two vocabularies for three kiosks, each with its own copy of the same
route map.

That is not cosmetic. A display reporting its own type sends what its file
says, so it could report a role core would not accept, and core could store
'partskiosk', a value no dispatcher would ever match. The enforcement report
column would have shown one vocabulary from the device and the other from the
DashboardDefault fallback, in the same column.

The machine's file wins, because that is what a person edits. DISPLAY_ROLE_PATHS
takes the kiosk spelling and the display scope now uses that dict rather than
holding a second one, so the two cannot drift again. normalize_display_role
resolves any casing and the retired 'partskiosk' forward; the dispatcher already
matched its map case-insensitively and the server now agrees with it.

Nothing is turned away over a capital: the API accepts any spelling and stores
the canonical one, displaypath resolves through the normalizer so rows written
before this keep working, and the settings dropdown canonicalises on open so an
old value does not render as a blank select.

A reported subtype is normalised on the way in, but an UNRECOGNISED one is kept
verbatim. That is a kiosk with a typo in its file or a role nobody declared, and
both are worth seeing in the fleet table rather than blanked or guessed at.

Contract bumped for the added names. DashboardDefault is finally listed in
__all__ too - 0.17.0 put it on the surface and never exported it.

shopdb/__init__.py

@@ -42,7 +42,13 @@ from .plugins import plugin_manager
 # first-time write under the declared category, and lets a plugin mark a key
 # readable without auth for pages that run logged out. Additive optional hook,
 # minor bump.
-__contract_version__ = '0.17.0'
+# 0.18.0: added DISPLAY_ROLES, DISPLAY_ROLE_PATHS and normalize_display_role
+# beside DashboardDefault (which 0.17.0 imported but never listed in __all__).
+# The role vocabulary is now the kiosk's own - Dashboard / Lobby / 3DPrintRoom,
+# the literal values of C:\Enrollment\display-type.txt - so a plugin holding its
+# own copy of that map (geenforce did) can read core's instead of drifting from
+# it. Additive names on the import surface, minor bump.
+__contract_version__ = '0.18.0'
 
 # Product release version (see ADR-007). The product version and the
 # plugin-contract version above are distinct series with independent