00a035ea20
Extends the interview-prep persistence pattern (previous commit) to the other two AI-generated per-job outputs that were re-running their full AI call chain on every tab open: candidate-fit (4 AI calls) and focus-plan (4 AI calls). Across all three tabs that's 9 AI calls fired every single time a user revisits a job's AI workspace tabs. Generalized into AiWorkspaceNote (OwnerUserId, JobApplicationId, NoteType, ResultJson) rather than duplicating InterviewPrepNote's per-field-column shape: CandidateFitDto and FocusPlanDto are irregular and nested (up to 13 fields including a nested guidance object), where per-field columns would be unreasonable. One table, keyed by note type, serving both. Same rules as interview prep: reuse across calls, regenerate when the attachment selection changes, regenerate on explicit refresh. Frontend gets the same "Regenerate" button on both tabs. 3 new tests (persist+reuse for both, refresh for candidate-fit). Verified against the real dev DB.