feat: Story 8 - Collapsible tool outputs + autonomous coding improvements

Implemented Story 8: Collapsible Tool Outputs
- Tool outputs now render in <details>/<summary> elements, collapsed by default
- Summary shows tool name with key argument (e.g., ▶ read_file(src/main.rs))
- Added arrow rotation animation and scrollable content (max 300px)
- Enhanced tool_calls display to show arguments inline
- Added CSS styling for dark theme consistency

Fixed: LLM autonomous coding behavior
- Strengthened system prompt with explicit examples and directives
- Implemented triple-reinforcement system (primary prompt + reminder + message prefixes)
- Improved tool descriptions to be more explicit and action-oriented
- Increased MAX_TURNS from 10 to 30 for complex agentic workflows
- Added debug logging for Ollama requests/responses
- Result: GPT-OSS (gpt-oss:20b) now successfully uses write_file autonomously

Documentation improvements
- Created MODEL_SELECTION.md guide with recommendations
- Updated PERSONA.md spec to emphasize autonomous agent behavior
- Updated UI_UX.md spec with collapsible tool output requirements
- Updated SDSW workflow: LLM archives stories and performs squash merge

Cleanup
- Removed unused ToolTester.tsx component

src-tauri/src/commands/chat.rs

@@ -17,7 +17,7 @@ pub struct ProviderConfig {
     pub enable_tools: Option<bool>,
 }
 
-const MAX_TURNS: usize = 10;
+const MAX_TURNS: usize = 30;
 
 #[tauri::command]
 pub async fn get_ollama_models(base_url: Option<String>) -> Result<Vec<String>, String> {
@@ -53,6 +53,16 @@ pub async fn chat(
     // 3. Agent Loop
     let mut current_history = messages.clone();
 
+    // Prefix user messages with reminder for stubborn models
+    for msg in &mut current_history {
+        if msg.role == Role::User && !msg.content.starts_with("[AGENT DIRECTIVE]") {
+            msg.content = format!(
+                "[AGENT DIRECTIVE: You must use write_file tool to implement changes. Never suggest code.]\n\n{}",
+                msg.content
+            );
+        }
+    }
+
     // Inject System Prompt
     current_history.insert(
         0,
@@ -64,6 +74,17 @@ pub async fn chat(
         },
     );
 
+    // Inject aggressive reminder as a second system message
+    current_history.insert(
+        1,
+        Message {
+            role: Role::System,
+            content: "CRITICAL REMINDER: When the user asks you to create, modify, or implement code, you MUST call the write_file tool with the complete file content. DO NOT output code in markdown blocks. DO NOT suggest what the user should do. TAKE ACTION IMMEDIATELY using tools.".to_string(),
+            tool_calls: None,
+            tool_call_id: None,
+        },
+    );
+
     let mut new_messages: Vec<Message> = Vec::new();
     let mut turn_count = 0;
 
@@ -91,8 +112,8 @@ pub async fn chat(
 
             current_history.push(assistant_msg.clone());
             new_messages.push(assistant_msg);
-            // Emit history excluding system prompt (index 0)
-            app.emit("chat:update", &current_history[1..])
+            // Emit history excluding system prompts (indices 0 and 1)
+            app.emit("chat:update", &current_history[2..])
                 .map_err(|e| e.to_string())?;
 
             // Execute Tools
@@ -110,8 +131,8 @@ pub async fn chat(
 
                 current_history.push(tool_msg.clone());
                 new_messages.push(tool_msg);
-                // Emit history excluding system prompt (index 0)
-                app.emit("chat:update", &current_history[1..])
+                // Emit history excluding system prompts (indices 0 and 1)
+                app.emit("chat:update", &current_history[2..])
                     .map_err(|e| e.to_string())?;
             }
         } else {
@@ -126,8 +147,8 @@ pub async fn chat(
             // We don't push to current_history needed for next loop, because we are done.
             new_messages.push(assistant_msg.clone());
             current_history.push(assistant_msg);
-            // Emit history excluding system prompt (index 0)
-            app.emit("chat:update", &current_history[1..])
+            // Emit history excluding system prompts (indices 0 and 1)
+            app.emit("chat:update", &current_history[2..])
                 .map_err(|e| e.to_string())?;
             break;
         }
@@ -200,11 +221,11 @@ fn get_tool_definitions() -> Vec<ToolDefinition> {
             kind: "function".to_string(),
             function: ToolFunctionDefinition {
                 name: "read_file".to_string(),
-                description: "Reads the content of a file in the project.".to_string(),
+                description: "Reads the complete content of a file from the project. Use this to understand existing code before making changes.".to_string(),
                 parameters: json!({
                     "type": "object",
                     "properties": {
-                        "path": { "type": "string", "description": "Relative path to the file" }
+                        "path": { "type": "string", "description": "Relative path to the file from project root" }
                     },
                     "required": ["path"]
                 }),
@@ -214,12 +235,12 @@ fn get_tool_definitions() -> Vec<ToolDefinition> {
             kind: "function".to_string(),
             function: ToolFunctionDefinition {
                 name: "write_file".to_string(),
-                description: "Writes content to a file. Overwrites if exists.".to_string(),
+                description: "Creates or completely overwrites a file with new content. YOU MUST USE THIS to implement code changes - do not suggest code to the user. The content parameter must contain the COMPLETE file including all imports, functions, and unchanged code.".to_string(),
                 parameters: json!({
                     "type": "object",
                     "properties": {
-                        "path": { "type": "string", "description": "Relative path to the file" },
-                        "content": { "type": "string", "description": "The full content to write" }
+                        "path": { "type": "string", "description": "Relative path to the file from project root" },
+                        "content": { "type": "string", "description": "The complete file content to write (not a diff or partial code)" }
                     },
                     "required": ["path", "content"]
                 }),
@@ -229,11 +250,11 @@ fn get_tool_definitions() -> Vec<ToolDefinition> {
             kind: "function".to_string(),
             function: ToolFunctionDefinition {
                 name: "list_directory".to_string(),
-                description: "Lists files and directories at a path.".to_string(),
+                description: "Lists all files and directories at a given path. Use this to explore the project structure.".to_string(),
                 parameters: json!({
                     "type": "object",
                     "properties": {
-                        "path": { "type": "string", "description": "Relative path to list (use '.' for root)" }
+                        "path": { "type": "string", "description": "Relative path to list (use '.' for project root)" }
                     },
                     "required": ["path"]
                 }),
@@ -243,12 +264,12 @@ fn get_tool_definitions() -> Vec<ToolDefinition> {
             kind: "function".to_string(),
             function: ToolFunctionDefinition {
                 name: "search_files".to_string(),
-                description: "Searches for text content across all files in the project."
+                description: "Searches for text patterns across all files in the project. Use this to find functions, variables, or code patterns when you don't know which file they're in."
                     .to_string(),
                 parameters: json!({
                     "type": "object",
                     "properties": {
-                        "query": { "type": "string", "description": "The string to search for" }
+                        "query": { "type": "string", "description": "The text pattern to search for across all files" }
                     },
                     "required": ["query"]
                 }),
@@ -258,18 +279,18 @@ fn get_tool_definitions() -> Vec<ToolDefinition> {
             kind: "function".to_string(),
             function: ToolFunctionDefinition {
                 name: "exec_shell".to_string(),
-                description: "Executes a shell command in the project root.".to_string(),
+                description: "Executes a shell command in the project root directory. Use this to run tests, build commands, git operations, or any command-line tool. Examples: cargo check, npm test, git status.".to_string(),
                 parameters: json!({
                     "type": "object",
                     "properties": {
                         "command": {
                             "type": "string",
-                            "description": "The command to run (e.g., 'git', 'cargo', 'ls')"
+                            "description": "The command binary to execute (e.g., 'git', 'cargo', 'npm', 'ls')"
                         },
                         "args": {
                             "type": "array",
                             "items": { "type": "string" },
-                            "description": "Arguments for the command"
+                            "description": "Array of arguments to pass to the command (e.g., ['status'] for git status)"
                         }
                     },
                     "required": ["command", "args"]