feat: centralize breadcrumbs in topbar and remove history navigation

Move breadcrumb rendering from individual page templates into the core
topbar. Each page now sets $breadcrumbs in its action .php file; the
topbar renders it automatically via the shared partial.

- Remove global back/forward buttons and app-nav-history.js component
- Remove Alt+Arrow keyboard shortcuts for history navigation
- Render breadcrumb in topbar-left section (replaces button area)
- Clean up breadcrumb CSS: context-neutral base (flex, no margin)
- Recalculate sticky titlebar offset in details container
- Migrate all 41 pages (core + helpdesk, audit, addressbook, api-docs)
- Add missing breadcrumbs to addressbook detail view
- Update architecture contract tests (nav-history references removed)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

web/js/app-init.js

@@ -5,7 +5,6 @@ import { initFlashAutoDismiss } from './components/app-flash-auto-dismiss.js';
 import { initPasswordHints } from './components/app-password-hints.js';
 import { initBadgeCopy } from './components/app-copy-badge.js';
 import { initMultiSelectComponent } from './components/app-multiselect-init.js';
-import { initNavHistory } from './components/app-nav-history.js';
 import { initSidebarToggle } from './components/app-toggle-sidebar.js';
 import { initAsidePanels } from './components/app-toggle-aside-panels.js';
 import { initDetailsAsideToggle } from './components/app-toggle-details-aside.js';
@@ -177,10 +176,6 @@ const bootRuntime = async () => {
     scope: 'global',
     configPath: 'components.multiSelect',
   });
-  runtime.register('nav-history', initNavHistory, {
-    selector: '[data-app-component="nav-history"]',
-    configPath: 'components.navHistory',
-  });
   runtime.register('details-state', initDetailsState, {
     scope: 'global',
     configPath: 'components.detailsState',

web/js/components/app-nav-history.js

@@ -1,96 +0,0 @@
-/**
- * Browser history integration — handles back/forward navigation state.
- */
-import { isEditableTarget } from '../core/app-form-utils.js';
-import { resolveHost } from '../core/app-dom.js';
-
-export function initNavHistory(root = document, options = {}) {
-  const {
-    backSelector = '#global-back',
-    forwardSelector = '#global-forward',
-  } = options;
-  const host = resolveHost(root);
-  const back = host.querySelector(backSelector);
-  const forward = host.querySelector(forwardSelector);
-  if (!back && !forward) {
-    return { destroy: () => {} };
-  }
-
-  const setDisabledState = (link, disabled) => {
-    link.setAttribute('aria-disabled', disabled ? 'true' : 'false');
-    link.classList.toggle('is-disabled', disabled);
-    if (disabled) {
-      link.setAttribute('tabindex', '-1');
-    } else {
-      link.removeAttribute('tabindex');
-    }
-  };
-
-  const updateHistoryButtons = () => {
-    const hasHistory = window.history.length > 1;
-    if (back instanceof HTMLElement) {
-      setDisabledState(back, !hasHistory);
-    }
-    if (forward instanceof HTMLElement) {
-      setDisabledState(forward, !hasHistory);
-    }
-  };
-
-  const onKeyDown = (event) => {
-    if (!event.altKey || event.metaKey || event.ctrlKey) {
-      return;
-    }
-    if (isEditableTarget(event.target)) {
-      return;
-    }
-    if (event.key === 'ArrowLeft') {
-      if (window.history.length > 1) {
-        event.preventDefault();
-        window.history.back();
-      }
-    } else if (event.key === 'ArrowRight') {
-      if (window.history.length > 1) {
-        event.preventDefault();
-        window.history.forward();
-      }
-    }
-  };
-
-  document.addEventListener('keydown', onKeyDown);
-
-  const onBackClick = (event) => {
-    event.preventDefault();
-    if (window.history.length > 1) {
-      window.history.back();
-    }
-  };
-  if (back instanceof HTMLElement) {
-    back.addEventListener('click', onBackClick);
-  }
-
-  const onForwardClick = (event) => {
-    event.preventDefault();
-    if (window.history.length > 1) {
-      window.history.forward();
-    }
-  };
-  if (forward instanceof HTMLElement) {
-    forward.addEventListener('click', onForwardClick);
-  }
-
-  window.addEventListener('popstate', updateHistoryButtons);
-  updateHistoryButtons();
-
-  const destroy = () => {
-    document.removeEventListener('keydown', onKeyDown);
-    if (back instanceof HTMLElement) {
-      back.removeEventListener('click', onBackClick);
-    }
-    if (forward instanceof HTMLElement) {
-      forward.removeEventListener('click', onForwardClick);
-    }
-    window.removeEventListener('popstate', updateHistoryButtons);
-  };
-
-  return { destroy, update: updateHistoryButtons };
-}