Add common_third_parties shared reference table

Introduce a globally-shared, non-tenant-scoped common_third_parties
table that mirrors the public subset of vendor metadata, plus a
one-shot cmd/common-third-parties-import CLI that seeds it from
packages/vendors/data.json. The catalog will back future flows (e.g.
vendor autocomplete) so each tenant no longer needs to duplicate the
same baseline data.

The importer is idempotent via ON CONFLICT (lower(name)) DO UPDATE
and prints inserted/updated counts. GIDs use gid.NilTenant since the
table is not tenant-scoped; uniqueness still comes from the entity
type plus 14 bytes of timestamp/random suffix.

Signed-off-by: Émile Ré <emile@getprobo.com>

pkg/coredata/migrations/20260508T083200Z.sql

@@ -0,0 +1,39 @@
+-- Copyright (c) 2026 Probo Inc <hello@getprobo.com>.
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted, provided that the above
+-- copyright notice and this permission notice appear in all copies.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+-- REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+-- AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+-- INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+-- LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+-- OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+-- PERFORMANCE OF THIS SOFTWARE.
+
+CREATE TABLE common_third_parties (
+    id                               TEXT PRIMARY KEY,
+    name                             TEXT NOT NULL,
+    description                      TEXT,
+    category                         vendor_category NOT NULL,
+    headquarter_address              TEXT,
+    legal_name                       TEXT,
+    website_url                      TEXT,
+    privacy_policy_url               TEXT,
+    service_level_agreement_url      TEXT,
+    service_software_agreement_url   TEXT,
+    data_processing_agreement_url    TEXT,
+    business_associate_agreement_url TEXT,
+    subprocessors_list_url           TEXT,
+    certifications                   TEXT[],
+    status_page_url                  TEXT,
+    terms_of_service_url             TEXT,
+    security_page_url                TEXT,
+    trust_page_url                   TEXT,
+    created_at                       TIMESTAMP WITH TIME ZONE NOT NULL,
+    updated_at                       TIMESTAMP WITH TIME ZONE NOT NULL
+);
+
+CREATE UNIQUE INDEX common_third_parties_name_key
+    ON common_third_parties (lower(name));