feat: Phase 3 - CRUD core for Techniques, Tests and Evidence (T-014 to T-017)

- Add Pydantic schemas for Technique, Test and Evidence
- Add CRUD endpoints for Techniques (list with filters, detail, create, update, review)
- Add CRUD endpoints for Tests (create, detail, update, validate, reject)
- Add evidence upload with SHA-256 integrity and presigned download URLs
- Add MinIO/S3 storage client with bucket auto-creation on startup
- Add status_service to recalculate technique coverage from test results
- Add require_any_role RBAC dependency for multi-role authorization
- Update README with API endpoints reference and project structure

backend/app/schemas/technique.py

@@ -0,0 +1,69 @@
+"""Pydantic schemas for Technique endpoints."""
+
+import uuid
+from datetime import datetime
+
+from pydantic import BaseModel, ConfigDict
+
+from app.models.enums import TechniqueStatus
+
+
+# ── Create ──────────────────────────────────────────────────────────
+
+class TechniqueCreate(BaseModel):
+    """Payload for creating a new technique."""
+
+    mitre_id: str
+    name: str
+    description: str | None = None
+    tactic: str | None = None
+    platforms: list[str] | None = None
+
+
+# ── Update ──────────────────────────────────────────────────────────
+
+class TechniqueUpdate(BaseModel):
+    """Payload for partially updating an existing technique.
+    Every field is optional so callers send only what changed."""
+
+    name: str | None = None
+    description: str | None = None
+    tactic: str | None = None
+    platforms: list[str] | None = None
+    status_global: TechniqueStatus | None = None
+
+
+# ── Read (full) ─────────────────────────────────────────────────────
+
+class TechniqueOut(BaseModel):
+    """Complete representation returned by the API."""
+
+    id: uuid.UUID
+    mitre_id: str
+    name: str
+    description: str | None = None
+    tactic: str | None = None
+    platforms: list[str] | None = None
+    mitre_version: str | None = None
+    mitre_last_modified: datetime | None = None
+    is_subtechnique: bool = False
+    parent_mitre_id: str | None = None
+    status_global: TechniqueStatus = TechniqueStatus.not_evaluated
+    review_required: bool = False
+    last_review_date: datetime | None = None
+
+    model_config = ConfigDict(from_attributes=True)
+
+
+# ── Read (summary) ──────────────────────────────────────────────────
+
+class TechniqueSummary(BaseModel):
+    """Lightweight representation used in list endpoints."""
+
+    id: uuid.UUID
+    mitre_id: str
+    name: str
+    tactic: str | None = None
+    status_global: TechniqueStatus = TechniqueStatus.not_evaluated
+
+    model_config = ConfigDict(from_attributes=True)