feat(ui): refine integration board view and compact assignees

Refactor the integration board UI to improve board discovery, loading,
and the card detail experience. Introduce a compact assignee mode and
apply it in list views to save horizontal space, and make several
accessibility and labeling improvements for board links and authors.

- Add a compact prop for assignee rendering and use it across lists.
- Improve board URL handling and add Azure DevOps board label parsing.
- Replace the old inspector with a focused detail drawer and sidebar.

src/lib/components/IssueCenter.svelte

@@ -211,7 +211,7 @@
               <button class="issue-row" class:selected={selectedId === issue.id} aria-pressed={selectedId === issue.id} onclick={event => { detailTrigger = event.currentTarget; selectedId = issue.id; actionError = ""; }}>
                 <span class="issue-identity"><span class="issue-number">#{issue.number}</span><span class="issue-text"><strong>{issue.title}</strong><small>{issue.repositoryName}</small><IssueLabels labels={issue.labels} /></span></span>
                 <span class="issue-status" data-tone={issueTone(issue.state)}><span class="status-dot"></span>{issueStateLabel(issue.state, de)}</span>
-                <IssueAssignees names={issue.assignees} />
+                <IssueAssignees names={issue.assignees} compact />
               </button>
               {/each}
               {/if}