Add company settings and number sequence API routes

- Add CompanySetting routes (list, get, set) backed by company-scoped store
- Add Number routes (list, update) for managing number sequences
- Register new store namespaces for numbers and companysetting
- Add CompanySetting and NumberSequence schemas to OpenAPI
- Regenerate API docs and index for the new routes

docs/api/routes/companysetting/list.md

@@ -0,0 +1,39 @@
+# `GET /company/setting`
+
+Protected. Requires a valid session cookie (`credentials: 'include'`).
+
+List company settings
+
+Returns the visible settings of the authenticated user's selected
+company: the full set of allowed keys (with `value: null` when unset)
+plus any stored settings that are frontend-visible. The `frontend`
+flag is stripped from responses.
+
+
+## Response `200`
+
+Company settings
+
+```json
+{
+  "settings": [
+    {
+      "key": "…",
+      "value": "…"
+    }
+  ]
+}
+```
+
+## Errors
+
+| Status | Description |
+|--------|-------------|
+| 400 | No company selected — `{"error":"…"}` |
+| 401 | Unauthorized — `{"error":"…"}` |
+| 403 | Not authorized — `{"error":"…"}` |
+| 404 | Company not found — `{"error":"…"}` |
+
+---
+
+_Generated from `@openapi` JSDoc. Do not edit by hand — run `npm run docs:api`._