fix: address CodeRabbit Phase 5 review feedback

Critical fixes:
- Fix invalid model names (gpt-5.1 → gpt-4o, claude-sonnet-4-5 → claude-sonnet-4-20250514)
- Add OpenAI key validation in MagenticOrchestrator with clear error message
- Document Magentic mode's OpenAI-only requirement

Nitpicks:
- Add streaming icon to AgentEvent.to_markdown()
- Use exact equality for PubMed placeholder detection
- Update app.py info text for API key requirements
- Add language identifiers to markdown code blocks in docs

docs/architecture/overview.md

@@ -65,7 +65,7 @@ Using existing approved drugs to treat NEW diseases they weren't originally desi
 
 ### High-Level Design (Phases 1-8)
 
-```
+```text
 User Query
     ↓
 Gradio UI (Phase 4)

docs/implementation/08_phase_report.md

@@ -11,7 +11,7 @@
 Current limitation: **Synthesis is basic markdown, not a scientific report.**
 
 Current output:
-```
+```markdown
 ## Drug Repurposing Analysis
 ### Drug Candidates
 - Metformin
@@ -22,7 +22,7 @@ Current output:
 ```
 
 With Report Agent:
-```
+```markdown
 ## Executive Summary
 One-paragraph summary for busy readers...
 
@@ -59,7 +59,7 @@ Properly formatted citations...
 ## 2. Architecture
 
 ### Phase 8 Addition
-```
+```text
 Evidence + Hypotheses + Assessment
             ↓
       Report Agent
@@ -68,7 +68,7 @@ Evidence + Hypotheses + Assessment
 ```
 
 ### Report Generation Flow
-```
+```text
 1. JudgeAgent says "synthesize"
 2. Magentic Manager selects ReportAgent
 3. ReportAgent gathers:

docs/implementation/roadmap.md

@@ -165,7 +165,7 @@ tests/
 
 ## Complete Architecture (Phases 1-8)
 
-```
+```text
 User Query
     ↓
 Gradio UI (Phase 4)

src/app.py

@@ -144,7 +144,7 @@ def create_demo() -> Any:
                     choices=["simple", "magentic"],
                     value="simple",
                     label="Orchestrator Mode",
-                    info="Simple: Linear loop | Magentic: Multi-Agent (Requires OpenAI Key)",
+                    info="Simple: Linear (OpenAI/Anthropic) | Magentic: Multi-Agent (OpenAI)",
                 )
             ],
         )

src/orchestrator_magentic.py

@@ -1,4 +1,9 @@
-"""Magentic-based orchestrator for DeepCritical."""
+"""Magentic-based orchestrator for DeepCritical.
+
+NOTE: Magentic mode currently requires OpenAI API keys. The MagenticBuilder's
+standard manager uses OpenAIChatClient. Anthropic support may be added when
+the agent_framework provides an AnthropicChatClient.
+"""
 
 from collections.abc import AsyncGenerator
 
@@ -17,6 +22,7 @@ from src.agents.judge_agent import JudgeAgent
 from src.agents.search_agent import SearchAgent
 from src.orchestrator import JudgeHandlerProtocol, SearchHandlerProtocol
 from src.utils.config import settings
+from src.utils.exceptions import ConfigurationError
 from src.utils.models import AgentEvent, Evidence
 
 logger = structlog.get_logger()
@@ -27,6 +33,11 @@ class MagenticOrchestrator:
     Magentic-based orchestrator - same API as Orchestrator.
 
     Uses Microsoft Agent Framework's MagenticBuilder for multi-agent coordination.
+
+    Note:
+        Magentic mode requires OPENAI_API_KEY. The MagenticBuilder's standard
+        manager currently only supports OpenAI. If you have only an Anthropic
+        key, use the "simple" orchestrator mode instead.
     """
 
     def __init__(
@@ -73,7 +84,13 @@ class MagenticOrchestrator:
         judge_agent = JudgeAgent(self._judge_handler, self._evidence_store)
 
         # Build Magentic workflow
-        # Note: MagenticBuilder.participants takes named arguments for agent instances
+        # Note: MagenticBuilder requires OpenAI - validate key exists
+        if not settings.openai_api_key:
+            raise ConfigurationError(
+                "Magentic mode requires OPENAI_API_KEY. "
+                "Set the key or use mode='simple' with Anthropic."
+            )
+
         workflow = (
             MagenticBuilder()
             .participants(

src/tools/pubmed.py

@@ -22,7 +22,7 @@ class PubMedTool:
     def __init__(self, api_key: str | None = None) -> None:
         self.api_key = api_key or settings.ncbi_api_key
         # Ignore placeholder values from .env.example
-        if self.api_key and "your-ncbi-key-here" in self.api_key:
+        if self.api_key == "your-ncbi-key-here":
             self.api_key = None
         self._last_request_time = 0.0
 

src/utils/config.py

@@ -26,8 +26,8 @@ class Settings(BaseSettings):
     llm_provider: Literal["openai", "anthropic"] = Field(
         default="openai", description="Which LLM provider to use"
     )
-    openai_model: str = Field(default="gpt-5.1", description="OpenAI model name")
-    anthropic_model: str = Field(default="claude-sonnet-4-5", description="Anthropic model")
+    openai_model: str = Field(default="gpt-4o", description="OpenAI model name")
+    anthropic_model: str = Field(default="claude-sonnet-4-20250514", description="Anthropic model")
 
     # PubMed Configuration
     ncbi_api_key: str | None = Field(

src/utils/models.py

@@ -125,6 +125,7 @@ class AgentEvent(BaseModel):
             "synthesizing": "📝",
             "complete": "🎉",
             "error": "❌",
+            "streaming": "📡",
         }
         icon = icons.get(self.type, "•")
         return f"{icon} **{self.type.upper()}**: {self.message}"