fix(print): fix app-wide printing and remove a global print-CSS leak

Root cause of blank/clipped print output across the app: the document root
(html/body) is globally locked to one viewport height with overflow hidden,
and Angular Material's drawer/tab-body containers each add their own
on-screen scroll clip on top of that. main.scss now frees the full chain for
print (document root, CDK drawer/sidenav containers, mat-tab-body, and the
account-view's mat-tab-nav-bar which was rendering as a stray grey scrollable
strip since it isn't covered by the mat-tab-group header rule already hidden).

Also fixed both certificate print dialogs (share-certificate-dialog,
deposit-certificate-dialog) reusing a `::ng-deep body > :not(.cdk-overlay-
container)` rule to hide the shell during their own print: under Angular's
style encapsulation this style is emitted fully unscoped into the global
stylesheet and is never removed once the component has loaded once in a
session, silently blanking every other page's print output for the rest of
the session. Dropped `::ng-deep` from that one selector so it goes back to
being properly scoped (and therefore inert, matching the other two dialogs
that never had this bug) — the app shell is already hidden for every print
via the global main.scss rules, so no dialog needs its own global override.

src/app/letter-mgmt/certificates/certificate-preview-dialog/certificate-preview-dialog.component.scss

@@ -576,13 +576,11 @@
 }
 
 /* ───────── Print — only the page, no toolbar / dialog chrome ─────────
-   This dialog is opened with `maxHeight: '92vh'`, which Angular Material carries onto the
-   overlay pane / .mat-mdc-dialog-container as an inline max-height + overflow:auto clip.
-   `position: absolute` still lives inside that clip and gets cut off — only the on-screen
-   scroll position prints. `position: fixed` escapes it: a fixed element's containing block is
-   the viewport itself, not the clipped ancestor (the classic "fixed child ignores an
-   overflow:hidden parent" behaviour), as long as nothing between here and the viewport sets a
-   transform/filter — the CDK overlay chrome doesn't. */
+   The document-level clip (`html, body { overflow: hidden }`) is lifted globally in main.scss's
+   print block; what remains here is this dialog's own clip — it opens with `maxHeight: '92vh'`,
+   which Angular Material carries onto the overlay pane / .mat-mdc-dialog-container as an inline
+   max-height plus overflow:auto. Freeing those lets the whole certificate flow onto the page in
+   normal static order (a fixed/absolute hack would pin it to the first page instead). */
 @media print {
   body > :not(.cdk-overlay-container) {
     display: none !important;
@@ -611,9 +609,7 @@
   }
 
   .cpd-root {
-    position: fixed;
-    left: 0;
-    top: 0;
+    position: static;
     width: 100% !important;
     height: auto !important;
     background: #fff;