fix: Windows unicode output and config model names

- Force UTF-8 stdout/stderr on Windows to handle LLM unicode output
- Replace ─ (U+2500) with - for Windows cp1251 compatibility
- Sanitize em-dash in session filenames
- Update default model to glm-5.1 in all roles

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

meeting_room/config/config.yaml

@@ -37,7 +37,7 @@ roles:
   moderator:
     name: "Moderator"
     provider: ollama_cloud
-    model: "gpt-4o-mini"
+    model: "glm-5.1"
     temperature: 0.7
     tools: "none"
     system_prompt: |
@@ -49,7 +49,7 @@ roles:
   skeptic:
     name: "Skeptic"
     provider: ollama_cloud
-    model: "gpt-4o-mini"
+    model: "glm-5.1"
     temperature: 0.9
     tools: "readonly"
     system_prompt: |
@@ -61,7 +61,7 @@ roles:
   idea_generator:
     name: "Idea Generator"
     provider: ollama_cloud
-    model: "gpt-4o-mini"
+    model: "glm-5.1"
     temperature: 1.0
     tools: "web"
     system_prompt: |
@@ -74,7 +74,7 @@ roles:
   analyst:
     name: "Analyst"
     provider: ollama_cloud
-    model: "gpt-4o-mini"
+    model: "glm-5.1"
     temperature: 0.5
     tools: "all"
     system_prompt: |
@@ -88,7 +88,7 @@ roles:
   defender:
     name: "Defender"
     provider: ollama_cloud
-    model: "gpt-4o-mini"
+    model: "glm-5.1"
     temperature: 0.6
     tools: "readonly"
     system_prompt: |
@@ -100,7 +100,7 @@ roles:
   attacker:
     name: "Attacker"
     provider: ollama_cloud
-    model: "gpt-4o-mini"
+    model: "glm-5.1"
     temperature: 0.9
     tools: "readonly"
     system_prompt: |
@@ -113,7 +113,7 @@ roles:
   security:
     name: "Security"
     provider: ollama_cloud
-    model: "gpt-4o-mini"
+    model: "glm-5.1"
     temperature: 0.4
     tools: "web"
     system_prompt: |