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).

packages/cli/src/connection-drivers.ts

@@ -0,0 +1,21 @@
+import type { KtxProjectConnectionConfig } from './context/project/config.js';
+
+const KTX_DATABASE_DRIVER_IDS = new Set([
+  'sqlite',
+  'postgres',
+  'mysql',
+  'clickhouse',
+  'sqlserver',
+  'bigquery',
+  'snowflake',
+]);
+
+export function normalizeConnectionDriver(connection: KtxProjectConnectionConfig): string {
+  return String(connection.driver ?? '')
+    .trim()
+    .toLowerCase();
+}
+
+export function isDatabaseDriver(driver: string): boolean {
+  return KTX_DATABASE_DRIVER_IDS.has(driver.trim().toLowerCase());
+}