朱子纯 / vibe-erp

feat(bootstrap): group OpenAPI spec by PBC / platform area

Adds 15 GroupedOpenApi beans that split the single giant OpenAPI
spec into per-PBC + per-platform-module focused specs selectable
from Swagger UI's top-right "Select a definition" dropdown. No
@RestController changes — all groups are defined by URL prefix
in platform-bootstrap, so adding a new PBC means touching exactly
this file (plus the controller itself). Each group stays
additive alongside the default /v3/api-docs.

**Groups shipped:**
  Platform
    platform-core     — /api/v1/auth/**, /api/v1/_meta/**
    platform-workflow — /api/v1/workflow/**
    platform-jobs     — /api/v1/jobs/**
    platform-files    — /api/v1/files/**
    platform-reports  — /api/v1/reports/**
  Core PBCs
    pbc-identity     — /api/v1/identity/**
    pbc-catalog      — /api/v1/catalog/**
    pbc-partners     — /api/v1/partners/**
    pbc-inventory    — /api/v1/inventory/**
    pbc-warehousing  — /api/v1/warehousing/**
    pbc-orders       — /api/v1/orders/** (sales + purchase together)
    pbc-production   — /api/v1/production/**
    pbc-quality      — /api/v1/quality/**
    pbc-finance      — /api/v1/finance/**
  Plug-in dispatcher
    plugins          — /api/v1/plugins/**

**Why path-prefix grouping, not package-scan grouping.**
Package-scan grouping would force OpenApiConfiguration to know
every PBC's Kotlin package name and drift every time a PBC ships
or a controller moves. Path-prefix grouping only shifts when
`@RequestMapping` changes — which is already a breaking API
change that would need review anyway. This keeps the control
plane for grouping in one file while the routing stays in each
controller.

**Why pbc-orders is one group, not split sales/purchase.**
Both controllers share the `/api/v1/orders/` prefix, and sales /
purchase are the same shape in practice — splitting them into
two groups would just duplicate the dropdown entries. A future
chunk can split if a real consumer asks for it.

**Primary group unchanged.** The default /v3/api-docs continues
to return the full merged spec (every operation in one
document). The grouped specs are additive at
/v3/api-docs/<group-name> and clients can pick whichever they
need. Swagger UI defaults to showing the first group in the
dropdown.

**Smoke-tested end-to-end against real Postgres:**
  - GET /v3/api-docs/swagger-config returns 15 groups with
    human-readable display names
  - Per-group path counts (confirming each group is focused):
    pbc-production: 10 paths
    pbc-catalog:     6 paths
    pbc-orders:     12 paths
    platform-core:   9 paths
    platform-files:  3 paths
    plugins:         1 path (dispatcher)
  - Default /v3/api-docs continues to return the full spec.

24 modules, 355 unit tests, all green.