Redesign document approval flow

Replace the per-approver add/remove model with a quorum-based approval
system. Documents now have default approvers that are pre-populated when
requesting approval, and the publish dialog lets users adjust the list
before submitting.

Key changes:

- Add PENDING_APPROVAL document version status with dedicated transitions
- Introduce approval quorums with request/approve/reject/void lifecycle
- Add default approvers per document (stored in document_default_approvers)
  with MERGE-based upsert for efficient sync
- Add NoDuplicates validator for slice fields
- Split ALTER TYPE ADD VALUE migrations into separate files (required by
  PostgreSQL when run inside transactions)
- Use VOIDED consistently for both quorum status and decision state enums
- Expose void/approve/reject through GraphQL and MCP, with e2e tests
- Add approval management UI: publish dialog with approver selection,
  approval list with void support, and external approve/reject page

Signed-off-by: Sacha Al Himdani <sacha@getprobo.com>

pkg/coredata/migrations/20260408T120000Z.sql

@@ -0,0 +1,17 @@
+-- Copyright (c) 2025-2026 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.
+
+ALTER TYPE document_version_status ADD VALUE 'PENDING_APPROVAL' BEFORE 'PUBLISHED';
+ALTER TYPE document_version_approval_quorum_status ADD VALUE 'VOIDED';
+ALTER TYPE document_version_approval_decision_state ADD VALUE 'VOIDED';

pkg/coredata/migrations/20260408T120004Z.sql

@@ -0,0 +1,35 @@
+-- Copyright (c) 2025-2026 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.
+
+-- Backfill: set every draft version that has a pending approval quorum to PENDING_APPROVAL
+UPDATE document_versions dv
+SET status = 'PENDING_APPROVAL'
+WHERE dv.status = 'DRAFT'
+  AND EXISTS (
+    SELECT 1
+    FROM document_version_approval_quorums q
+    WHERE q.version_id = dv.id
+      AND q.status = 'PENDING'
+  );
+
+-- Backfill: void pending decisions in rejected or voided quorums
+UPDATE document_version_approval_decisions d
+SET state = 'VOIDED'
+WHERE d.state = 'PENDING'
+  AND EXISTS (
+    SELECT 1
+    FROM document_version_approval_quorums q
+    WHERE q.id = d.quorum_id
+      AND q.status IN ('REJECTED', 'VOIDED')
+  );

pkg/coredata/migrations/20260408T130000Z.sql

@@ -0,0 +1,47 @@
+-- Copyright (c) 2025-2026 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 document_default_approvers (
+    document_id         text                     NOT NULL,
+    approver_profile_id text                     NOT NULL,
+    tenant_id           text                     NOT NULL,
+    organization_id     text                     NOT NULL,
+    created_at          timestamp with time zone NOT NULL,
+    updated_at          timestamp with time zone NOT NULL,
+    PRIMARY KEY (document_id, approver_profile_id),
+    FOREIGN KEY (document_id) REFERENCES documents(id) ON UPDATE CASCADE ON DELETE CASCADE,
+    FOREIGN KEY (approver_profile_id) REFERENCES iam_membership_profiles(id) ON UPDATE CASCADE ON DELETE CASCADE
+);
+
+-- Backfill default approvers from the last quorum of the last version of each document.
+INSERT INTO document_default_approvers (document_id, approver_profile_id, tenant_id, organization_id, created_at, updated_at)
+SELECT DISTINCT
+    dv.document_id,
+    d.approver_id,
+    d.tenant_id,
+    d.organization_id,
+    d.created_at,
+    d.created_at
+FROM document_version_approval_decisions d
+JOIN document_version_approval_quorums q ON q.id = d.quorum_id
+JOIN document_versions dv ON dv.id = q.version_id
+WHERE q.id = (
+    SELECT q2.id
+    FROM document_version_approval_quorums q2
+    JOIN document_versions dv2 ON dv2.id = q2.version_id
+    WHERE dv2.document_id = dv.document_id
+    ORDER BY dv2.created_at DESC, q2.created_at DESC
+    LIMIT 1
+)
+ON CONFLICT (document_id, approver_profile_id) DO NOTHING;