fix(reports): stop driving report queries from the unfiltered journal_entry_lines side (#971)

* fix(reports): drive report line queries from journal_entries, not the unfiltered lines side

Every report generator fetched journal_entry_lines with a
journal_entries!inner(...) embed and put the tenant filter on the
embedded side (.eq('journal_entries.company_id', ...)). PostgREST
compiles that to a correlated INNER JOIN LATERAL with a parameterized
LIMIT inside, which blocks join reordering: Postgres walked the ENTIRE
journal_entry_lines table (603k rows, all tenants) per report query.
Measured in production: 13.6 s vs 2.7 ms for the equivalent plain join,
against Supabase's 8 s statement_timeout; nightly cloud backups failed
for 5 of 11 companies on 2026-07-09 and a GL report 500'd.

Introduce lib/bookkeeping/entry-lines.ts with a shared two-step fetch:

1. fetch matching journal_entries (id + caller-selected columns)
   filtered by company_id / fiscal_period_id / status / entry_date /
   source_type, paginated via fetchAllRows;
2. fetch journal_entry_lines with .in('journal_entry_id', chunk) in
   chunks of 100 ids (URL-length safety), paginated per chunk;
3. reattach the parent entry to each line under the embed's key shape
   (line.journal_entries = {...}, aliasable) and sort lines by id
   ascending to preserve the old .order('id') semantics.

Converted call sites (selected columns and filters preserved):
trial-balance (x2), general-ledger, journal-register, sie-export
(reuses its existing entry list via fetchLinesByEntryIds),
vat-declaration, dimension-pnl, opening-balances, monthly-breakdown,
periodisk-sammanstallning, rc-basis-gaps (sibling-line fetch now also
chunked), ar-reconciliation, supplier-reconciliation,
bank-reconciliation, asset-service (x2), bolagsskatt-calculator,
sarskild-loneskatt-calculator.

Tests: unit tests for the helper (chunk size, reattachment shape,
forced id/journal_entry_id columns, empty result, cross-chunk sort,
error propagation); existing report/reconciliation/bokslut test mocks
updated to the two-step query shape, preserving every assertion about
report output.

From the 2026-07-09 production log triage.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(reports): stop echoing raw error messages from the general-ledger route

The catch handler returned err.message to the client in
details.reason; internal error strings (SQL fragments, table names,
timeout messages) must not reach the browser. The error is already
logged server-side with the request id, so the client envelope keeps
only the REPORT_GENERATION_FAILED code.

From the 2026-07-09 production log triage.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

app/api/reports/general-ledger/route.ts

@@ -29,11 +29,10 @@ export const GET = withRouteContext(
       })
       return NextResponse.json({ data })
     } catch (err) {
+      // The raw error message is logged server-side only: it can carry
+      // internal details (SQL, table names) that must not reach the client.
       log.error('general ledger generation failed', err as Error, { periodId })
-      return errorResponseFromCode('REPORT_GENERATION_FAILED', log, {
-        requestId,
-        details: { reason: err instanceof Error ? err.message : 'unknown' },
-      })
+      return errorResponseFromCode('REPORT_GENERATION_FAILED', log, { requestId })
     }
   },
 )