fix(jira): correct browse URL, rename Procedure to Proof of Concept; feat(tempo): debug endpoint + UI

Jira URL fix:
- JiraLinkPanel now fetches the configured Jira base URL via getJiraConfig()
  instead of hardcoding https://jira.atlassian.com; falls back to the old
  value if config is not yet loaded

Description fix:
- _build_test_description: renamed 'h3. Procedure' -> 'h3. Proof of Concept'
  so the procedure/tool block maps to the correct Jira field label

Tempo debug:
- New POST /system/tempo-test endpoint: checks TEMPO_ENABLED, token,
  user jira_account_id, and makes a real API call; always returns HTTP 200
  with status field (Cloudflare-safe)
- docker-compose.prod.yml: added TEMPO_ENABLED, TEMPO_API_TOKEN,
  TEMPO_DEFAULT_WORK_TYPE env vars (default off, ready to enable)
- SettingsPage: added 'Test Tempo Connection' button in Jira admin tab
  with clear feedback showing what's missing

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/components/JiraLinkPanel.tsx

@@ -20,6 +20,7 @@ import {
   type JiraLinkEntityType,
   type JiraIssueResult,
 } from "../api/jira";
+import { getJiraConfig } from "../api/settings";
 import { useDebounce } from "../hooks/useDebounce";
 
 interface JiraLinkPanelProps {
@@ -49,6 +50,14 @@ export default function JiraLinkPanel({ entityType, entityId }: JiraLinkPanelPro
 
   // ── Queries ─────────────────────────────────────────────────────
 
+  const { data: jiraConfig } = useQuery({
+    queryKey: ["jira-config"],
+    queryFn: getJiraConfig,
+    staleTime: 5 * 60 * 1000,
+  });
+
+  const jiraBaseUrl = jiraConfig?.url?.replace(/\/$/, "") ?? "https://jira.atlassian.com";
+
   const { data: links = [], isLoading: isLoadingLinks } = useQuery({
     queryKey: ["jira-links", entityType, entityId],
     queryFn: () => listJiraLinks({ entity_type: entityType, entity_id: entityId }),
@@ -247,7 +256,7 @@ export default function JiraLinkPanel({ entityType, entityId }: JiraLinkPanelPro
                     />
                   </button>
                   <a
-                    href={`https://jira.atlassian.com/browse/${link.jira_issue_key}`}
+                    href={`${jiraBaseUrl}/browse/${link.jira_issue_key}`}
                     target="_blank"
                     rel="noopener noreferrer"
                     title="Open in Jira"