refactor(cli): delete internal barrel index.ts files

The 34 `index.ts` re-export barrels inside `packages/cli/src/` were
holdovers from the pre-fold multi-workspace structure. Post-fold-in they
served no production purpose: external consumers go through the single
package main entry, and in-repo callers mostly imported through them
only because the path was short. Internally, knip flagged most barrel
re-exports as production-dead (only reached via tests).

This change:
- Deletes every internal barrel except `packages/cli/src/index.ts`
  (the published package entry).
- Rewrites ~270 source/test files to import each name directly from
  the file that defines it.
- Moves `tools/warehouse-verification/index.ts` to
  `create-warehouse-verification-tools.ts` (the function it defined
  locally) and updates its single consumer.
- Renames `search/backend-conformance.ts` → `.test-utils.ts` to match
  the existing test-helper file convention.
- Deletes 13 dead test-only chains (dbt-descriptions/*,
  live-database/extracted-schema, live-database/structural-sync,
  relationship-* feedback/review chain) plus their tests and a
  cascading orphan integration test.
- Updates test mocks that pointed at deleted barrel paths
  (notion-client, connector barrels in scan/local-scan-connectors
  tests) to mock the source files instead.
- Points the maintainer benchmark script
  (`scripts/relationship-benchmark-report.mjs`) at source files
  instead of `dist/context/scan/index.js`.
- Drops the barrel `!` entries from `knip.json`; adds explicit
  production entries only for the benchmark code reached via dist by
  the maintainer script.

Net: 413 files changed, ~1.2k insertions, ~9.4k deletions.

`pnpm run dead-code` (Biome + knip default + knip production) and
`pnpm run type-check` are clean; 2277 tests pass.

knip.json

@@ -2,48 +2,41 @@
   "$schema": "https://unpkg.com/knip@6/schema.json",
   "workspaces": {
     ".": {
-      "entry": ["scripts/**/*.mjs"],
-      "project": ["scripts/**/*.mjs"],
-      "ignoreDependencies": [
-        "@semantic-release/commit-analyzer",
-        "@semantic-release/github",
-        "@semantic-release/npm",
-        "@semantic-release/release-notes-generator",
-        "conventional-changelog-conventionalcommits"
+      "entry": [
+        "scripts/**/*.mjs",
+        "scripts/**/*.cjs",
+        ".releaserc.cjs!"
       ]
     },
     "packages/cli": {
       "entry": [
-        "src/llm/index.ts!",
-        "src/context/**/index.ts!",
-        "src/connectors/*/index.ts!",
         "src/print-command-tree.ts!",
+        "scripts/**/*.mjs",
         "src/**/*.test-utils.ts",
-        "src/**/acceptance-fixtures.ts"
-      ],
-      "project": ["src/**/*.{ts,tsx}!", "scripts/**/*.mjs", "vitest.config.ts"]
+        "src/**/acceptance-fixtures.ts",
+        "src/context/scan/relationship-benchmarks.ts!",
+        "src/context/scan/relationship-benchmark-report.ts!"
+      ]
     },
     "docs-site": {
       "entry": [
         "components/**/*.{ts,tsx}!",
         "source.config.ts!"
       ],
-      "project": [
-        "app/**/*.{ts,tsx}!",
-        "components/**/*.{ts,tsx}!",
-        "lib/**/*.{ts,tsx}!",
-        "*.ts!",
-        "*.mjs",
-        "tests/**/*.mjs"
-      ],
-      "ignoreDependencies": ["tailwindcss"]
+      "ignoreDependencies": [
+        "tailwindcss"
+      ]
     }
   },
-  "ignore": [
-    "**/dist/**",
-    "**/coverage/**",
-    "**/.next/**",
-    "**/node_modules/**"
+  "ignoreDependencies": [
+    "@semantic-release/commit-analyzer",
+    "@semantic-release/github",
+    "@semantic-release/npm",
+    "@semantic-release/release-notes-generator",
+    "conventional-changelog-conventionalcommits"
   ],
-  "ignoreBinaries": ["uv", "lsof"]
+  "ignoreBinaries": [
+    "uv",
+    "lsof"
+  ]
 }