refactor(mana): rename inventar → inventory across the codebase

The workbench-registry app id 'inventar' did not match its
@mana/shared-branding MANA_APPS counterpart 'inventory', so the tier-
gating join in apps/web/src/lib/app-registry/registry.ts silently
failed for the inventory module — it fell into the "no MANA_APPS
entry, default visible" fallback and was effectively un-gated. The
codebase had also voted overwhelmingly for 'inventar' (53 files) vs
'inventory' (3 files in shared-branding), so the long-standing
mismatch was just bookkeeping debt waiting to bite.

Pre-release, no live data, so the cleanest fix is to align everything
on the English 'inventory':

- Workbench-registry id, module.config.ts appId, module folder, route
  folder and i18n locale folder all renamed via git mv
- Standalone apps/inventar/ workspace package renamed
- All imports, store identifiers (InventarEvents → InventoryEvents,
  INVENTAR_GUEST_SEED, inventarModuleConfig), i18n keys and href/goto
  paths follow the rename
- The German display label "Inventar" is preserved everywhere it is a
  user-visible string (page titles, i18n values, toast labels)
- Dexie table prefixes (invCollections, invItems, …) are unchanged
- Drive-by fix: ListView.svelte was querying non-existent
  inventarCollections/inventarItems tables — corrected to the actual
  invCollections/invItems names from module.config
- The "inventar ↔ inventory id mismatch" workaround comment in
  registry.ts is removed since the mismatch no longer exists

module-registry.ts also picks up the user's parallel newsModuleConfig
addition because both edits land in the same import block — keeping
them split would have left the build in an inconsistent state.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/PORT_SCHEMA.md

@@ -133,7 +133,7 @@ Pure CRUD apps use mana-sync directly.
 | 5022 | citycorners-web | *(local-first only)* |
 | 5023 | cards-web | 3036 cards-server |
 | 5024 | mukke-web | 3037 mukke-server |
-| 5025 | inventar-web | *(local-first only)* |
+| 5025 | inventory-web | *(local-first only)* |
 | 5026 | context-web | *(local-first only)* |
 | 5027 | questions-web | *(local-first only)* |
 | 5028 | planta-web | 3039 planta-server |