Add risk publish to document system

Replace the old snapshot-based system for risks with the publish
document system, mirroring the prior vendor / processing activity / DPIA
/ TIA migration. Includes the GraphQL mutation, MCP tool, CLI command,
n8n operation, frontend publish dialog, e2e tests, and a prosemirror
register template covering name, description, category, treatment,
owner, inherent and residual scoring, and notes.

The risk register lives as a generated DocumentTypeRegister document on
the organization, reused across publishes (the major version bumps on
every republish). Approvers can be passed in to create a draft pending
approval; otherwise the version is published immediately. The frontend
Risks page exposes a Publish button and a Document link button when the
document exists, and pre-fills the previous default approvers.

Risks was the last remaining snapshot type, so this commit also removes
the entire snapshot system: drop snapshotId from the Risk GraphQL type
and RiskFilter; remove RiskSnapshotter, Risks.Snapshot,
InsertRiskSnapshots, and the SnapshotID/SourceID fields on Risk; delete
Snapshot, ControlSnapshot, SnapshotsType, SnapshotOrderField,
Snapshottable, the SnapshotService, the Snapshot console resolvers and
GraphQL schema, the Snapshot MCP types and operations
(list/get/take/listControlSnapshots), the snapshot CLI (prb snapshot),
the snapshot frontend pages, routes, banner, LinkedSnapshotsCard,
SnapshotGraph, snapshot helpers, and the snapshot n8n resource and
control link/unlink snapshot operations. The snapshot_id columns remain
in the database but are now filtered out with snapshot_id IS NULL.

Add Get/Upsert/Clear GeneratedDocumentID methods on Risk backed by a new
risks_document_id column on generated_documents, matching the
ProcessingActivity/Finding/Vendor pattern. The migration command
migrate-risk-snapshots-to-documents uses raw SQL queries instead of the
Go snapshot types, since those are gone.

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

pkg/docgen/generator.go

@@ -259,6 +259,35 @@ type (
 		Vendors         string
 	}
 
+	RiskListData struct {
+		Title            string
+		OrganizationName string
+		CreatedAt        time.Time
+		TotalRisks       int
+		Rows             []RiskListRow
+	}
+
+	RiskListRow struct {
+		Name                    string
+		Description             string
+		Category                string
+		Treatment               string
+		Owner                   string
+		InherentLikelihood      int
+		InherentLikelihoodLabel string
+		InherentImpact          int
+		InherentImpactLabel     string
+		InherentRiskScore       int
+		InherentSeverity        string
+		ResidualLikelihood      int
+		ResidualLikelihoodLabel string
+		ResidualImpact          int
+		ResidualImpactLabel     string
+		ResidualRiskScore       int
+		ResidualSeverity        string
+		Note                    string
+	}
+
 	FindingListData struct {
 		Title            string
 		OrganizationName string