fix: differentiate security action links and add suppression editing (#1500)

Security page UX fixes:

- Stop the CVSS x EPSS scatter chart from painting a full-plot "white
  rectangle" cursor on click (cursor disabled), and prevent click-drag
  selection on charts.
- Differentiate the overview action links: "fixable" links (masthead primary
  action, review-queue blocker, and the Fixable signal tile) now open the
  Images tab pre-filtered to fixable findings; the Stale and Failed signal
  tiles link to the History tab where those scans are listed; Secrets and
  Misconfigs tiles link to their tabs. The Images tab accepts an initialFilter
  and exposes a Fixable option in the severity dropdown.
- Fix the "Secrets / misconfigs" option wrapping and misaligning in the
  severity dropdown (single-line option labels, wider trigger).
- Add Edit for CVE suppressions and misconfig acknowledgements (reason, scope
  pattern, expiry), reusing the existing dialog and the existing PUT endpoints;
  the CVE/rule identity stays fixed.

frontend/src/types/security.ts

@@ -263,6 +263,9 @@ export interface PostureReason {
 export interface PostureAction {
   label: string;
   targetTab: SecurityTab;
+  /** The reason kind behind this action, so the UI can target the affected
+   *  items precisely (e.g. filter Images to fixable findings). */
+  kind: PostureReasonKind;
 }
 
 /** Node-scoped security posture rollup for the Security page Overview. */