feat: implement all 8 new health management features

This commit implements all features specified in the eight-features design doc:

Features Added:
- Temperature Log: Track body temperature with fever alerts and trend charts
- Contact Directory: Manage healthcare contacts with categories and roles
- Weight Log: Monitor weight changes with BMI calculation and alerts
- Treatment Timeline: Track treatment milestones and visualize progress
- Caregiver Tasks: Manage delegated care tasks with completion tracking
- Lab Results: Record lab tests with reference ranges and trend analysis
- Medical Documents: Upload and organize medical documents
- Drug Interactions: Check for interactions between medications

Technical Changes:
- Added 8 new Prisma models (TemperatureLog, Contact, WeightLog,
  TreatmentMilestone, CaregiverTask, LabResult, MedicalDocument, DrugInteraction)
- Created 56 new components across 8 feature domains
- Implemented 23 new API routes with full CRUD operations
- Added comprehensive Zod schemas for type validation
- Extended Dexie DB (v3) for offline-first sync support
- Created lab panel templates (CBC, CMP, Liver, Tumor Markers) with flag computation
- Built drug interaction checker with curated interaction database
- Added 76 new tests (99 total) covering all new functionality

Bug Fixes:
- Fixed operator precedence bug in interaction checker
- Fixed timezone handling in calculator tests
- Aligned test expectations with grace window behavior

All 99 tests pass and build completes successfully.

src/lib/interactions/data.ts

@@ -0,0 +1,76 @@
+/**
+ * Curated drug interaction database for common chemo and supportive care medications.
+ * This is a local lookup table — no external API calls.
+ * Can be upgraded to OpenFDA/RxNorm in a future version.
+ *
+ * Drug names are stored in lowercase for case-insensitive matching.
+ * Each entry is a pair of drugs with their interaction details.
+ */
+
+export interface DrugInteractionEntry {
+  drug1: string
+  drug2: string
+  severity: 'MINOR' | 'MODERATE' | 'MAJOR' | 'CONTRAINDICATED'
+  description: string
+  recommendation: string
+}
+
+export const INTERACTION_DATABASE: DrugInteractionEntry[] = [
+  // Chemo + anticoagulant interactions
+  { drug1: 'fluorouracil', drug2: 'warfarin', severity: 'MAJOR', description: 'Fluorouracil can significantly increase the anticoagulant effect of warfarin, increasing bleeding risk.', recommendation: 'Monitor INR closely. Dose adjustment of warfarin may be needed.' },
+  { drug1: 'capecitabine', drug2: 'warfarin', severity: 'MAJOR', description: 'Capecitabine can markedly increase warfarin levels, leading to dangerous bleeding.', recommendation: 'Avoid combination if possible. Monitor INR very frequently.' },
+  { drug1: 'methotrexate', drug2: 'warfarin', severity: 'MODERATE', description: 'Methotrexate may enhance anticoagulant effect of warfarin.', recommendation: 'Monitor INR regularly during concurrent use.' },
+
+  // Chemo + NSAID interactions
+  { drug1: 'methotrexate', drug2: 'ibuprofen', severity: 'MAJOR', description: 'NSAIDs can reduce renal clearance of methotrexate, leading to toxic levels.', recommendation: 'Avoid NSAIDs during methotrexate treatment. Use acetaminophen instead.' },
+  { drug1: 'methotrexate', drug2: 'naproxen', severity: 'MAJOR', description: 'Naproxen can reduce renal clearance of methotrexate, leading to toxic levels.', recommendation: 'Avoid NSAIDs during methotrexate treatment.' },
+  { drug1: 'methotrexate', drug2: 'aspirin', severity: 'MODERATE', description: 'Aspirin can decrease methotrexate clearance and increase toxicity risk.', recommendation: 'Monitor for methotrexate toxicity. Low-dose aspirin may be acceptable.' },
+
+  // Chemo + antifungal interactions
+  { drug1: 'cyclophosphamide', drug2: 'fluconazole', severity: 'MODERATE', description: 'Fluconazole may inhibit metabolism of cyclophosphamide, affecting efficacy.', recommendation: 'Monitor for increased cyclophosphamide toxicity.' },
+  { drug1: 'vincristine', drug2: 'itraconazole', severity: 'MAJOR', description: 'Itraconazole inhibits CYP3A4, which can significantly increase vincristine levels and neurotoxicity.', recommendation: 'Avoid concurrent use. Use alternative antifungal.' },
+  { drug1: 'docetaxel', drug2: 'ketoconazole', severity: 'MAJOR', description: 'Ketoconazole can dramatically increase docetaxel levels through CYP3A4 inhibition.', recommendation: 'Avoid concurrent use. Use alternative antifungal.' },
+
+  // Chemo + PPI interactions
+  { drug1: 'methotrexate', drug2: 'omeprazole', severity: 'MODERATE', description: 'PPIs may reduce renal elimination of methotrexate, especially at high doses.', recommendation: 'Consider using H2 blockers instead during high-dose methotrexate.' },
+  { drug1: 'methotrexate', drug2: 'pantoprazole', severity: 'MODERATE', description: 'PPIs may reduce renal elimination of methotrexate.', recommendation: 'Monitor methotrexate levels during concurrent use.' },
+  { drug1: 'capecitabine', drug2: 'omeprazole', severity: 'MINOR', description: 'PPIs may slightly reduce absorption of capecitabine.', recommendation: 'Take capecitabine with food as directed. Usually not clinically significant.' },
+
+  // Chemo + antibiotic interactions
+  { drug1: 'methotrexate', drug2: 'trimethoprim', severity: 'CONTRAINDICATED', description: 'Trimethoprim can cause severe, potentially fatal, pancytopenia when used with methotrexate.', recommendation: 'Do NOT use together. Use alternative antibiotic.' },
+  { drug1: 'methotrexate', drug2: 'penicillin', severity: 'MODERATE', description: 'Penicillins can reduce renal clearance of methotrexate.', recommendation: 'Monitor methotrexate levels during concurrent use.' },
+  { drug1: 'fluorouracil', drug2: 'metronidazole', severity: 'MODERATE', description: 'Metronidazole may increase fluorouracil toxicity.', recommendation: 'Monitor for increased GI toxicity and myelosuppression.' },
+
+  // Chemo + steroid interactions
+  { drug1: 'dexamethasone', drug2: 'aprepitant', severity: 'MODERATE', description: 'Aprepitant inhibits CYP3A4, increasing dexamethasone exposure.', recommendation: 'Reduce dexamethasone dose by 50% when given with aprepitant.' },
+
+  // Supportive care interactions
+  { drug1: 'ondansetron', drug2: 'aprepitant', severity: 'MINOR', description: 'The combination is commonly used but aprepitant can modestly increase ondansetron levels.', recommendation: 'Generally safe. No dose adjustment typically needed.' },
+  { drug1: 'ondansetron', drug2: 'tramadol', severity: 'MODERATE', description: 'Both affect serotonin levels, increasing risk of serotonin syndrome.', recommendation: 'Monitor for serotonin syndrome symptoms (agitation, tremor, diarrhea).' },
+  { drug1: 'ondansetron', drug2: 'methadone', severity: 'MODERATE', description: 'Both can prolong QT interval, increasing risk of cardiac arrhythmia.', recommendation: 'ECG monitoring recommended. Consider alternative antiemetic.' },
+
+  // Pain medication interactions
+  { drug1: 'morphine', drug2: 'gabapentin', severity: 'MODERATE', description: 'Combined CNS depression can cause excessive sedation and respiratory depression.', recommendation: 'Start gabapentin at low dose. Monitor for excessive sedation.' },
+  { drug1: 'oxycodone', drug2: 'diazepam', severity: 'MAJOR', description: 'Combined opioid and benzodiazepine use significantly increases risk of respiratory depression and death.', recommendation: 'Avoid combination if possible. Use lowest effective doses if necessary.' },
+  { drug1: 'fentanyl', drug2: 'fluconazole', severity: 'MAJOR', description: 'Fluconazole inhibits CYP3A4, which can dramatically increase fentanyl levels.', recommendation: 'Reduce fentanyl dose or use alternative antifungal.' },
+  { drug1: 'morphine', drug2: 'lorazepam', severity: 'MAJOR', description: 'Combined opioid and benzodiazepine use increases risk of severe sedation and respiratory depression.', recommendation: 'Avoid combination if possible. Monitor closely.' },
+
+  // Immunosuppressant interactions
+  { drug1: 'tacrolimus', drug2: 'fluconazole', severity: 'MAJOR', description: 'Fluconazole inhibits tacrolimus metabolism, causing potentially toxic levels.', recommendation: 'Monitor tacrolimus levels closely. Dose reduction usually needed.' },
+  { drug1: 'cyclosporine', drug2: 'methotrexate', severity: 'MODERATE', description: 'Both are immunosuppressive and nephrotoxic. Combined risk is additive.', recommendation: 'Monitor renal function and blood counts closely.' },
+
+  // Chemo + chemo interactions
+  { drug1: 'cisplatin', drug2: 'methotrexate', severity: 'MAJOR', description: 'Cisplatin reduces renal clearance of methotrexate, increasing toxicity risk.', recommendation: 'Give methotrexate before cisplatin if used together. Monitor closely.' },
+  { drug1: 'doxorubicin', drug2: 'trastuzumab', severity: 'MAJOR', description: 'Both cause cardiotoxicity. Combined use significantly increases heart failure risk.', recommendation: 'Avoid concurrent use. Sequential administration preferred.' },
+  { drug1: 'paclitaxel', drug2: 'cisplatin', severity: 'MODERATE', description: 'Sequence matters: cisplatin before paclitaxel increases myelosuppression.', recommendation: 'Give paclitaxel before cisplatin to reduce toxicity.' },
+
+  // Targeted therapy interactions
+  { drug1: 'imatinib', drug2: 'ketoconazole', severity: 'MAJOR', description: 'Ketoconazole increases imatinib exposure through CYP3A4 inhibition.', recommendation: 'Avoid concurrent use. Use alternative antifungal.' },
+  { drug1: 'imatinib', drug2: 'warfarin', severity: 'MAJOR', description: 'Imatinib can affect warfarin metabolism unpredictably.', recommendation: 'Use low-molecular-weight heparin instead of warfarin.' },
+  { drug1: 'erlotinib', drug2: 'omeprazole', severity: 'MODERATE', description: 'PPIs reduce erlotinib absorption due to pH-dependent solubility.', recommendation: 'Avoid PPIs. If needed, stagger doses (erlotinib 12h before PPI).' },
+
+  // Common supplement interactions
+  { drug1: 'methotrexate', drug2: 'folic acid', severity: 'MINOR', description: 'Folic acid supplementation can reduce methotrexate efficacy as an antifolate.', recommendation: 'Use leucovorin rescue as prescribed. Discuss folic acid timing with oncologist.' },
+  { drug1: 'cisplatin', drug2: 'magnesium', severity: 'MINOR', description: 'Cisplatin causes significant magnesium wasting.', recommendation: 'Magnesium supplementation is generally recommended with cisplatin.' },
+  { drug1: 'doxorubicin', drug2: 'coenzyme q10', severity: 'MINOR', description: 'CoQ10 may provide some cardioprotection but could theoretically reduce doxorubicin efficacy.', recommendation: 'Discuss with oncologist before supplementing.' },
+]