Call them compositions; single-source WELL_TIERS

The data layer has said compositions since the catalog was split, while the
code, the model-facing text, and the UI still said stagings. The rename was
held back by the selection logic existing twice; it exists once now, so this
is one pass instead of two coordinated ones.

Renamed: selectApprovedStagings, selectApprovedStaging, renderStaging, and
the model-facing STAGING GRAMMAR / STAGING CHALLENGERS / FIRST-SURFACE
STAGING INPUTS headings. The block that introduces them now states what
they are for rather than only what they are not: what is the cleverest way
to present, organize, or make interactive the problem in front of you.

Three places keep the old word on purpose:

- The rank salt, `${scope}:${key}:staging`. It is hash input, so renaming
  it would re-deal every roll anyone has ever reproduced by key. Verified:
  240 seeder rolls and 252 API rolls reproduce exactly.
- `Staging/hierarchy:`, the first composition grammar prefix. Inside a
  composition, staging names one of its four aspects, which is a different
  word-sense from staging as the name for the whole artifact. It is also a
  schema constant that 317 catalog entries are validated against.
- The wire fields. The API keeps emitting `stagings` and `staging` beside
  `compositions`, because the wire is the one place a rename cannot be
  coordinated with already-installed skills. Clients prefer the new field
  and fall back through both old ones.

Separately, WELL_TIERS had two definitions after the extraction.
roll-selection.mjs owns it now and concept-catalog.mjs imports it, in that
direction because concept-catalog reads the filesystem and a Pages Function
must not pull node:fs into its bundle. Imported and re-exported rather than
re-exported alone: a bare `export { X } from` does not bind X locally, and
validateConceptCatalog needs it, which cost one round of red tests.

Dropped concept-catalog's synchronous deterministicRank. Nothing imports it
since selection moved out, and leaving a second ranking implementation
around is how the first drift started.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

skill/scripts/lib/composition-catalog.mjs

@@ -2,7 +2,7 @@ import crypto from 'node:crypto';
 import { readFileSync } from 'node:fs';
 import { CONCEPT_STATUSES, normalizeConceptForm } from './concept-catalog.mjs';
 
-// Catalog B: stagings rather than styles. A composition organizes attention,
+// Catalog B: compositions rather than styles. A composition organizes attention,
 // sequence, or manipulation on a surface and must survive being dressed in
 // any committed visual identity; it deliberately carries no palette or type
 // half. Surface-scope seeds draw from here (plus catalog A duals); direction
@@ -15,8 +15,8 @@ export const COMPOSITION_GRAMMAR_PREFIXES = [
   'Adaptation:',
 ];
 
-// Surfaces align with the skill's modes: a persuade staging and an operate
-// staging are different species, and read/experience surfaces get their own.
+// Surfaces align with the skill's modes: a persuade composition and an operate
+// composition are different species, and read/experience surfaces get their own.
 export const COMPOSITION_SURFACES = new Set(['persuade', 'operate', 'read', 'experience']);
 
 export function compositionContentHash(composition) {