security: update dependencies to fix dependabot vulnerabilities (Phase 1)

- cryptography: 46.0.7 → 47.0.0 (fixes 4 high-severity vulnerabilities)
- ecdsa: 0.19.2 → 0.19.3 (fixes timing attack vulnerability)
- black: 26.3.1 → 26.4.0 (fixes arbitrary file writes)
- orjson: 3.11.8 → 3.11.9 (fixes recursion limit issue)
- python-multipart: 0.0.6 → 0.0.25 (fixes 3 high-severity vulnerabilities)

Updated in:
- requirements.txt
- apps/coordinator-api/src/app/services/multi_language/requirements.txt

This resolves ~20/72 dependabot alerts with low-risk minor version updates.

apps/coordinator-api/src/app/services/multi_language/requirements.txt

@@ -7,7 +7,7 @@ Dependencies and requirements for multi-language support
 fastapi>=0.104.0
 uvicorn[standard]>=0.24.0
 pydantic>=2.5.0
-python-multipart>=0.0.6
+python-multipart>=0.0.25
 
 # Translation providers
 openai>=1.3.0
@@ -50,10 +50,10 @@ rich>=13.7.0
 tqdm>=4.66.0
 
 # Security
-cryptography>=41.0.0
+cryptography>=47.0.0
 python-jose[cryptography]>=3.3.0
 passlib[bcrypt]>=1.7.4
 
 # Performance
-orjson>=3.9.0
+orjson>=3.11.9
 lz4>=4.3.0