feat(phase-35): Jira + Tempo integration with internal worklogs

Full Jira/Tempo pipeline: link Aegis entities to Jira issues, auto-sync
status hourly, log time internally with integrity hashing, and optionally
push worklogs to Tempo.

- 1.1 JiraLink model + Worklog model: Alembic migration b020 with indexes,
  enums (jiralinkentitytype, jirasyncdirection), and integrity_hash column
- 1.2 Jira service: atlassian-python-api wrapper with lazy singleton client,
  search/create/sync operations, feature-flagged via JIRA_ENABLED
- 1.3 Jira router: CRUD endpoints for /jira/links, /jira/search,
  /jira/create-issue with audit logging and entity-to-issue auto-creation
- 1.4 Tempo service: worklog push via tempo-api-python-client, auto-log from
  test completions when TEMPO_ENABLED, graceful fallback on failure
- 1.5 Worklog service + router: immutable internal time records with SHA-256
  integrity hash, CRUD at /worklogs, /worklogs/{id}/verify endpoint
- 1.6 Frontend: JiraLinkPanel component (search, link, sync, unlink) and
  WorklogTimeline component (timeline view, manual log form) integrated into
  TestDetailPage sidebar, CampaignDetailPage grid, TechniqueDetailPage
- 1.7 Jira sync job: APScheduler hourly job syncs all links from Jira,
  registered in background scheduler alongside existing jobs

backend/requirements.txt

@@ -18,6 +18,7 @@ pydantic-settings
 slowapi
 defusedxml
 redis>=5.0.0
+atlassian-python-api>=4.0.0
 
 # Testing
 pytest