feat: pre-deploy scan visibility and pinned scanner version (#1378)

* feat: pre-deploy scan visibility and pinned scanner version

Pin managed Trivy installs and add an opt-in pre-deploy scan advisory so a
manual deploy can surface each image's latest scan before it runs.

- Managed Trivy now installs a pinned, known-good version by default for
  reproducible installs. Auto-update still tracks the latest release, and an
  explicit update always pulls the latest.
- Add an opt-in pre-deploy scan advisory: when enabled, deploying a stack from
  the editor first shows each image's latest cached scan severity for review.
  It is visibility only and never blocks; deploy enforcement is unchanged.
- Backend: pre_deploy_scan_advisory setting, PUT
  /security/pre-deploy-scan-advisory, a cache-only GET
  /security/stacks/:name/pre-deploy-summary, and a node-scoped
  getLatestVulnScanByDigestForNode lookup.
- Frontend: advisory toggle on the Security page scanner setup, and a
  PreDeployScanDialog wired into the editor deploy flow that fails open when the
  summary is unavailable.
- Docs: scanner configuration, version pinning, and the advisory.

* fix: harden pre-deploy advisory guard, toggle visibility, and installer busy state

Addresses review findings on the pre-deploy advisory.

- Block a second editor deploy during the async advisory window with a
  synchronous pending ref, cleared on cancel and in the deploy's finally, so a
  double-click can no longer start two deploys.
- Keep the pre-deploy advisory toggle visible to admins whenever the setting is
  on, so it can still be turned off after the scanner becomes unavailable.
- Resolve the managed Trivy version inside the install lock so the busy state and
  serialization cover the latest-version fetch and the managed-install check.

backend/src/services/DatabaseService.ts

@@ -588,6 +588,13 @@ export interface VulnerabilityScan {
     policy_evaluation: string | null;
 }
 
+// Fail-closed allowlist of the scanners_used values that ran the vulnerability
+// scanner. Image scans store vuln/secret joins from normalizeScanners (TrivyService),
+// while compose scans store 'config' directly; listing only the vuln-bearing sets
+// means any other value (secret-only, config, or a future literal) is excluded, so
+// a clean vuln read can never be a secret-only or config scan in disguise.
+export const VULN_BEARING_SCANNER_SETS = ['vuln', 'vuln,secret'] as const;
+
 export function parsePolicyEvaluation(raw: string | null | undefined): PolicyEvaluation | null {
     if (!raw) return null;
     try {
@@ -1458,6 +1465,7 @@ export class DatabaseService {
         stmt.run('trivy_auto_update', '0');
         stmt.run('trivy_last_notified_version', '');
         stmt.run('deploy_block_honor_suppressions', '0');
+        stmt.run('pre_deploy_scan_advisory', '0');
         stmt.run('mesh_auto_recreate', '0');
         stmt.run('prune_on_update', '1');
         stmt.run('reclaim_hero', '1');
@@ -4226,6 +4234,26 @@ export class DatabaseService {
         );
     }
 
+    /**
+     * Latest completed vulnerability-bearing scan for a digest ON A SPECIFIC NODE.
+     *
+     * Unlike getLatestScanByDigest, this filters by node_id so a read-only
+     * response never surfaces a scan (or scan id) produced on another node, and
+     * it restricts to scanner sets that actually ran the vulnerability scanner so
+     * a secret-only or config scan is not mistaken for a clean vuln scan.
+     */
+    public getLatestVulnScanByDigestForNode(digest: string, nodeId: number): VulnerabilityScan | null {
+        if (!digest) return null;
+        const placeholders = VULN_BEARING_SCANNER_SETS.map(() => '?').join(', ');
+        return (
+            (this.db
+                .prepare(
+                    `SELECT * FROM vulnerability_scans WHERE image_digest = ? AND node_id = ? AND status = 'completed' AND scanners_used IN (${placeholders}) ORDER BY scanned_at DESC LIMIT 1`,
+                )
+                .get(digest, nodeId, ...VULN_BEARING_SCANNER_SETS) as VulnerabilityScan | undefined) ?? null
+        );
+    }
+
     public deleteOldScans(olderThanMs: number): number {
         const cutoff = Date.now() - olderThanMs;
         const result = this.db