feat: add code-review scenario and cross-LLM review roles

- scenarios/code-review.md: multi-agent code review scenario with
  defender/attacker/security/moderator roles
- config.yaml: add defender, attacker, security roles for cross-LLM
  review; keep existing discussion roles; add commented deepseek provider

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

meeting_room/config/config.yaml

@@ -9,6 +9,9 @@ providers:
   routerai:
     base_url: "https://routerai.ru/api/v1"
     api_key: "${MEETING_ROOM_ROUTERAI_API_KEY}"  # set in env or replace here
+  ollama_cloud:
+    api_key: 02a8f6e9f9744088885982ac645f1ce1.HB1MFh4AlTpyic9oJGxQjNuA
+    base_url: https://ollama.com/v1
 
   # openai:
   #   base_url: "https://api.openai.com/v1"
@@ -22,13 +25,18 @@ providers:
   #   base_url: "http://localhost:11434/v1"
   #   api_key: "ollama"
 
+  # deepseek:
+  #   base_url: "https://api.deepseek.com/v1"
+  #   api_key: "${MEETING_ROOM_DEEPSEEK_API_KEY}"
+
 # ─── Roles ───
 # tools: all | full | files | readonly | web | none | or list ["read_file", "web_search"]
 
 roles:
+  # ── General discussion ──
   moderator:
     name: "Moderator"
-    provider: routerai
+    provider: ollama_cloud
     model: "gpt-4o-mini"
     temperature: 0.7
     tools: "none"
@@ -40,7 +48,7 @@ roles:
 
   skeptic:
     name: "Skeptic"
-    provider: routerai
+    provider: ollama_cloud
     model: "gpt-4o-mini"
     temperature: 0.9
     tools: "readonly"
@@ -52,7 +60,7 @@ roles:
 
   idea_generator:
     name: "Idea Generator"
-    provider: routerai
+    provider: ollama_cloud
     model: "gpt-4o-mini"
     temperature: 1.0
     tools: "web"
@@ -65,7 +73,7 @@ roles:
 
   analyst:
     name: "Analyst"
-    provider: routerai
+    provider: ollama_cloud
     model: "gpt-4o-mini"
     temperature: 0.5
     tools: "all"
@@ -76,6 +84,45 @@ roles:
       Propose concrete action plans.
       Use tools to verify facts, read project files, and search for info.
 
+  # ── Code review ──
+  defender:
+    name: "Defender"
+    provider: ollama_cloud
+    model: "gpt-4o-mini"
+    temperature: 0.6
+    tools: "readonly"
+    system_prompt: |
+      You wrote this code. Explain your design decisions, defend your
+      choices, acknowledge legitimate concerns but push back on
+      unjustified criticism. Reference specific files and line numbers
+      when explaining your logic. Read the code files being reviewed.
+
+  attacker:
+    name: "Attacker"
+    provider: ollama_cloud
+    model: "gpt-4o-mini"
+    temperature: 0.9
+    tools: "readonly"
+    system_prompt: |
+      You are a ruthless code reviewer. Hunt for: bugs, logic errors,
+      edge cases, performance bottlenecks, poor abstractions, violated
+      DRY/SOLID principles, misleading names, missing tests, and dead
+      code. Don't be polite — be precise. Cite specific lines.
+      Use read_file and search_in_files to examine the code thoroughly.
+
+  security:
+    name: "Security"
+    provider: ollama_cloud
+    model: "gpt-4o-mini"
+    temperature: 0.4
+    tools: "web"
+    system_prompt: |
+      You are a security specialist. Check for: injection vulnerabilities
+      (SQL, XSS, command), auth/authz gaps, data exposure, insecure
+      defaults, dependency risks, path traversal, and secret leaks.
+      Use web_search to check for known CVEs in dependencies.
+      Be specific — cite exact code locations and explain the attack vector.
+
 defaults:
   max_rounds: 8
   language: "ru"