feat(cli)!: remove fast mode; ktx ingest always builds enriched context (KLO-721) (#237)

Fast mode (the ktx ingest --fast/--deep database-ingest depth toggle) is removed.
ktx ingest now always builds the full enriched ("deep") context. There is no
structural fallback: a database connection without a configured model and
embeddings fails the enrichment-readiness preflight before any work runs, with
a 'Run ktx setup to configure a model and embeddings' hint.

- Remove --fast/--deep flags, the per-connection context.depth field, and the
  ktx setup depth prompt (delete setup-database-context-depth.ts).
- Rename ingest-depth.ts -> connection-drivers.ts; ingest always requests scan
  mode 'enriched'; readiness gate (enrichmentReadinessGaps) runs for every
  database target.
- Drop the database-context-depth telemetry step (Node + Python schema mirrors
  regenerated).
- Update CLI, setup, context-build view, docs, the public ktx skill, and the
  release-smoke / artifacts scripts (now assert the no-LLM guard failure).

ktx status --fast (a separate network-probe flag) is unchanged.

Follow-ups: KLO-726 (live progress for ktx ingest --all), KLO-727 (restore
credentialed successful-ingest release smoke coverage).

docs/terminology.md

@@ -77,8 +77,6 @@ maintains, validates, and serves that layer.
 | Connection ref in prose | **connection id** (lowercase, two words) | "connection ID" |
 | CLI arg/flag literal | `connectionId` (code font) | — |
 | File path placeholder | `<connection-id>` (code font) | — |
-| Fast schema mode | **fast ingest** | schema ingest, schema-only ingest |
-| AI-enriched mode | **deep ingest** | AI-enriched ingest |
 | Ingest of a primary connection | **database ingest** | — |
 | Ingest of a context-source connection | **context-source ingest** | bare "source ingest" |
 | Wiki capture | **text ingest** | — |