perf(requests): index the request list in paging order (#61)

CHANGELOG.md

@@ -74,6 +74,8 @@ This file records what changes **in the product** – process and session state
 
 ### Changed
 - AI service logs use the web/worker format: `time` (ISO 8601, `Z`) instead of `ts`, lower-case pino level labels (`warn`, not `WARNING`), `logger` only on library records.
+- The request list reads each page from an index in its sort order instead of sorting all of the
+  company's requests (#61).
 
 ### Fixed
 - AI verifier: a unit quoted together with the neighbouring table cell (e.g. `60    | Stk.`) is now

docs/technical/data-model.md

@@ -39,7 +39,8 @@ query sees zero rows and every write fails.
 | `rejection_reason` | text | free-text reason of a rejection, max 1000 chars (refused above, not cut – review module); also in the `request.rejected` audit event | confidential |
 
 Unique `(id, company_id)` so child tables can pin the company with composite foreign keys (FK checks
-bypass RLS). Purpose: one quote request per row. Retention: open question for the customer (ADR-0001 open points).
+bypass RLS). Index `(company_id, created_at desc, id desc)` serves the paged request list (#48, #61) and
+every lookup by company. Purpose: one quote request per row. Retention: open question for the customer (ADR-0001 open points).
 
 ### `app.extraction_runs`, `app.extraction_segments`, `app.extracted_fields` – processing results (#7)
 

src/db/migrations/0017_request_list_index.sql

@@ -0,0 +1,2 @@
+DROP INDEX "app"."requests_company_id_idx";--> statement-breakpoint
+CREATE INDEX "requests_company_created_idx" ON "app"."requests" USING btree ("company_id","created_at" DESC NULLS FIRST,"id" DESC NULLS FIRST);