fix: use only actual entries as source of truth for registry numbers

The previous fix still used MAX(actualMax, counterVal) which meant a
stale counter (from entries deleted before the fix was deployed) would
override the actual entry count. Changed to use ONLY actualMax + 1.

The RegistrySequence counter is now just a cache that gets synced —
it never overrides the actual entries count.

Also added /api/registratura/debug-sequences endpoint:
- GET: shows all counters vs actual entry max (for diagnostics)
- POST: resets all counters to match actual entries (one-time fix)

After deploy, call POST /api/registratura/debug-sequences to reset
the stale counters, then delete the BTG-2026-OUT-00004 entry and
recreate it — it will get 00001.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/modules/registratura/services/registry-service.ts

@@ -261,19 +261,14 @@ export async function allocateSequenceNumber(
     `;
     const actualMax = maxRows[0]?.maxSeq ?? 0;
 
-    // 2. Also read the current counter as a safety net (should never be
-    //    higher than actualMax if everything is consistent, but we take
-    //    the MAX of both just in case).
-    const counterRows = await tx.$queryRaw<Array<{ lastSeq: number }>>`
-      SELECT "lastSeq" FROM "RegistrySequence"
-      WHERE company = ${companyPrefix} AND year = ${yr} AND type = ${typeCode}
-    `;
-    const counterVal = counterRows[0]?.lastSeq ?? 0;
+    // 2. Next sequence = actual entries max + 1.
+    //    Entries in KeyValueStore are the SOLE source of truth.
+    //    The RegistrySequence counter is only a cache — if it drifted
+    //    (e.g. entries were deleted before the recalculate fix), we
+    //    ignore it entirely and reset it to match reality.
+    const nextSeq = actualMax + 1;
 
-    // 3. Next sequence = max(actual entries, counter) + 1
-    const nextSeq = Math.max(actualMax, counterVal) + 1;
-
-    // 4. Upsert the counter to the new value
+    // 3. Upsert the counter to the new value (keep it in sync)
     await tx.$executeRaw`
       INSERT INTO "RegistrySequence" (id, company, year, type, "lastSeq", "createdAt", "updatedAt")
       VALUES (gen_random_uuid()::text, ${companyPrefix}, ${yr}, ${typeCode}, ${nextSeq}, NOW(), NOW())