The backend entry knew its type and the CLI dropped it

[EronWright]

What

config_show's index gives every entry an address that spells out its type — random_pet.this, module.vpc, var.region. The backend is the exception: its address is the bare word backend, so the server carries the backend type on the entry itself. configShowView never decoded that field, so the one entry whose identity its address cannot hold rendered as backend · backend.

How

• Hoist the anonymous entry struct into a named configShowEntryView and decode type.
• Give it label(), which appends the backend type when there is one — backend local, the same pair config_init's summary already prints (renderers.go:2390).
• Route both the detail rows and the single-entry compact summary through it: a single-address query is the shape this is usually read in, and with results hidden that line is the whole answer.

Non-backend entries have no type and read exactly as before.

Lockstep

Pairs with turfbuild/doof#137, which made the backend a plot unit and put type on the config_show entry for both dialects (plot and tofu). The field is omitempty, so this renderer is correct against an older server too — it just never sees the field.

That PR also removed config_show's config map; configShowView never decoded it, so nothing here breaks and nothing here needed to change for it.

Verified

• go vet ./... clean; new tests TestConfigShow_BackendCarriesItsType and TestConfigShow_SingleBackendSummary pass, as do the renderer guard tests (TestEveryTurfToolHasRenderer, TestEveryRendererLeadsWithTitle, TestRenderers_BadJSONFallsBack).
• Full suite: one pre-existing failure unrelated to this change — TestPermissionListsMatchServerAnnotations reports turf_action_trigger / turf_action_untrigger missing from preApprovedTurfTools. Red on clean main locally; it skips in CI (no server on PATH).