chore: Update project configuration and improve chat prompts

Configuration Updates:
- .claude/settings.local.json: Add security permissions for WebFetch, WebSearch, nvidia-smi
- package.json: Add puppeteer dependency for browser automation tests
- package-lock.json: Update lockfile with puppeteer@24.34.0 and dependencies
- Remove root .env.example (superseded by generations/library_rag/.env.example)

Flask App Improvements:
- Enhanced chat prompt to REQUIRE "Sources utilisées" section in responses
- Added explicit warnings against inventing citations not in provided passages
- Improved source citation format with mandatory author, work, and passage number
- Strengthened instructions to prevent hallucinated references

Benefits:
- Chat responses now consistently include proper source citations
- Better academic rigor in philosophical analyses
- Prevents LLM from inventing non-existent references
- Automated testing infrastructure with Puppeteer

Related to GPU embedder migration testing and validation.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

.claude/settings.local.json

@@ -54,7 +54,21 @@
       "Bash(pytest:*)",
       "Bash(start test_sans_beige.html)",
       "Bash(ollama list:*)",
-      "Bash(done)"
+      "Bash(done)",
+      "WebFetch(domain:github.com)",
+      "Bash(nvidia-smi:*)",
+      "Bash(scriptsinstall_pytorch_cuda.bat)",
+      "Bash(cmd /c scripts\\\\install_pytorch_cuda.bat)",
+      "Bash(pip uninstall:*)",
+      "Bash(pip cache:*)",
+      "Bash(wmic process where \"name=''python.exe''\" get processid,commandline)",
+      "Bash(if [ -f \"/tmp/parse_output.log\" ])",
+      "Bash(then tail -100 /tmp/parse_output.log)",
+      "Bash(else echo \"Fichier log non trouvé\")",
+      "Bash(fi)",
+      "WebSearch",
+      "WebFetch(domain:weaviate.io)",
+      "WebFetch(domain:docs.weaviate.io)"
     ]
   }
 }