fix(search): S1/W1/W3/W4/S3/S5/S2 — required-term details, CAP note, restored guards (#529)

S1: fetchDetails now builds rank/highlight/matchedFields from the same
[...positive, ...required] set matchedTerms uses, so a required-only query
(`+кофейня`) no longer reports matchedFields:[] / rank:null.

W1: documented that CANDIDATE_CAP bounds pagination reachability (JS-side), not
query compute — a SQL LIMIT would corrupt the exact permission-filtered total.

S2: one-line note that literal-`%`/`_` search was intentionally dropped (total:0).

W3: restored the trgm-index EXPLAIN guard (search-lookup-explain.int-spec) that
asserts the coalesce-free substring predicates use idx_pages_*_trgm, not Seq Scan.

W4: added an integration ordering test proving title-exact > title-substring >
text-only tier dominance under RRF.

S3: added a test that an exact-title hit survives a tiny CANDIDATE_CAP window.

S5: server pretest now also builds @docmost/mcp so the ToolWriteClass import
resolves from clean CI (mirrors editor-ext/prosemirror-markdown).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/server/package.json

@@ -23,7 +23,7 @@
     "migration:reset": "tsx src/database/migrate.ts down-to NO_MIGRATIONS",
     "migration:codegen": "kysely-codegen --dialect=postgres --camel-case --env-file=../../.env --out-file=./src/database/types/db.d.ts",
     "lint": "eslint \"{src,apps,libs,test}/**/*.ts\" --fix",
-    "pretest": "pnpm --filter @docmost/editor-ext build && pnpm --filter @docmost/prosemirror-markdown build && pnpm --filter @docmost/token-estimate build",
+    "pretest": "pnpm --filter @docmost/editor-ext build && pnpm --filter @docmost/prosemirror-markdown build && pnpm --filter @docmost/token-estimate build && pnpm --filter @docmost/mcp build",
     "test": "jest",
     "test:int": "jest --config test/jest-integration.json",
     "test:watch": "jest --watch",