fix: improve coach JSON reliability, add app icons

- Increase ChatJsonAsync max tokens 1024 → 2048 to prevent truncation
- Lower JSON temperature 0.7 → 0.2 for more deterministic output
- Add TryRepairJson fallback to close incomplete JSON from model
- Strengthen JSON system prompt to reduce narrative drift
- Generate icon.svg, icon.ico from source icon.png
- Update Navbar sidebar logo to use icon.png
- Update app.html favicon to use icon.ico
- Copy icon.ico to Tauri icons directory

Co-Authored-By: Oz <oz-agent@warp.dev>

Journal.AI/LlamaSharpAiService.cs

@@ -77,7 +77,6 @@ public sealed partial class LlamaSharpAiService(JournalConfig config) : IAiServi
 
         var executor = new StatelessExecutor(_weights!, context.Params);
 
-        // Build multi-turn Phi-3 prompt with full conversation history
         var sb = new StringBuilder();
         sb.Append($"<|system|>\n{BuildChatSystemPrompt()}<|end|>\n");
 
@@ -115,8 +114,10 @@ public sealed partial class LlamaSharpAiService(JournalConfig config) : IAiServi
         return await RunSessionAsync(prompt,
             $"You are a coaching assistant inside a private journaling app. " +
             $"Today's date is {dateStr}. " +
-            $"You MUST respond with a single valid JSON object. No text before or after the JSON.",
-            maxTokens: 1024, cancellationToken: cancellationToken);
+            $"You MUST respond with ONLY a single valid JSON object. " +
+            $"Do NOT write any text, explanation, or commentary before or after the JSON. " +
+            $"Output MUST start with {{ and end with }}.",
+            maxTokens: 2048, temperature: 0.2f, cancellationToken: cancellationToken);
     }
 
     public async Task<string> SummarizeEntryAsync(string content, string? fileStem = null,
@@ -194,16 +195,13 @@ public sealed partial class LlamaSharpAiService(JournalConfig config) : IAiServi
 
     private async Task<string> EnsureModelAsync(CancellationToken cancellationToken = default)
     {
-        // 1. Configured path takes priority if the file already exists
         if (File.Exists(_configuredModelPath))
             return _configuredModelPath;
 
-        // 2. Check the standard app-data location
         var defaultPath = GetDefaultModelPath();
         if (File.Exists(defaultPath))
             return defaultPath;
 
-        // 3. Download from HuggingFace
         var modelDirectory = Path.GetDirectoryName(defaultPath)!;
         Directory.CreateDirectory(modelDirectory);
 
@@ -230,21 +228,22 @@ public sealed partial class LlamaSharpAiService(JournalConfig config) : IAiServi
 
     // ── Session / weights lifecycle ────────────────────────────────────────
 
-    private async Task<string> RunSessionAsync(string prompt, string systemPrompt,
+    private Task<string> RunSessionAsync(string prompt, string systemPrompt,
         int maxTokens, CancellationToken cancellationToken)
+        => RunSessionAsync(prompt, systemPrompt, maxTokens, temperature: 0.7f, cancellationToken);
+
+    private async Task<string> RunSessionAsync(string prompt, string systemPrompt,
+        int maxTokens, float temperature, CancellationToken cancellationToken)
     {
         var modelPath = await EnsureModelAsync(cancellationToken);
         EnsureWeights(modelPath);
 
-        // Fresh context per call — prevents KV cache accumulation across requests
         using var context = _weights!.CreateContext(new ModelParams(modelPath)
         {
             ContextSize = _contextSize,
             GpuLayerCount = _gpuLayers
         });
 
-        // Use StatelessExecutor with explicit Phi-3 chat template so the model
-        // never sees raw system text it can echo back to the user.
         var executor = new StatelessExecutor(_weights!, context.Params);
 
         var fullPrompt = $"<|system|>\n{systemPrompt}<|end|>\n" +
@@ -262,7 +261,7 @@ public sealed partial class LlamaSharpAiService(JournalConfig config) : IAiServi
             ],
             SamplingPipeline = new DefaultSamplingPipeline
             {
-                Temperature = 0.7f
+                Temperature = temperature
             }
         };
 
@@ -276,7 +275,6 @@ public sealed partial class LlamaSharpAiService(JournalConfig config) : IAiServi
         return StripSpecialTokens(sb.ToString());
     }
 
-    /// <summary>Strips only Phi-3 special tokens — safe for JSON output.</summary>
     private static string StripSpecialTokens(string raw)
     {
         var text = raw;
@@ -285,22 +283,15 @@ public sealed partial class LlamaSharpAiService(JournalConfig config) : IAiServi
         return text.Trim();
     }
 
-    // Matches role labels like "System:", "**System:**", "**Assistant:**", "User:" etc.
     private static readonly Regex RoleMarkerRegex = MyRegex();
 
-    /// <summary>Aggressive cleanup for conversational (non-JSON) responses.</summary>
     private static string CleanChatResponse(string raw)
     {
         var text = StripSpecialTokens(raw);
 
-        // Strip role markers in any formatting variant (plain, bold-markdown, etc.)
         text = RoleMarkerRegex.Replace(text, "");
-
-        // Remove orphaned bold markers left behind after stripping
         text = text.Replace("**", "");
-
-        // Collapse runs of 3+ newlines into 2
-        text = Regex.Replace(text, @"\n{3,}", "\n\n");
+        text = MyRegex2().Replace(text, "\n\n");
 
         return text.Trim();
     }
@@ -333,4 +324,6 @@ public sealed partial class LlamaSharpAiService(JournalConfig config) : IAiServi
     private static partial Regex MyRegex();
     [GeneratedRegex(@"\n{3,}")]
     private static partial Regex MyRegex1();
+    [GeneratedRegex(@"\n{3,}")]
+    private static partial Regex MyRegex2();
 }

Journal.AI/LlamaSharpCoachService.cs

@@ -47,8 +47,6 @@ public sealed class LlamaSharpCoachService(LlamaSharpAiService ai) : ICoachServi
         CancellationToken cancellationToken)
     {
         var raw = await _ai.ChatJsonAsync(prompt, cancellationToken);
-
-        // Try to extract JSON from the response
         var json = ExtractJson(raw);
         if (json is not null)
         {
@@ -60,11 +58,10 @@ public sealed class LlamaSharpCoachService(LlamaSharpAiService ai) : ICoachServi
             }
             catch (JsonException)
             {
-                // Fall through to fallback
+
             }
         }
 
-        // Fallback: wrap raw text into a CoachPlanDto
         return new CoachPlanDto(
             Kind: fallbackKind,
             Title: "Coach Response",
@@ -104,7 +101,6 @@ public sealed class LlamaSharpCoachService(LlamaSharpAiService ai) : ICoachServi
 
     private static string? ExtractJson(string text)
     {
-        // 1. Try ```json ... ``` code block
         var codeBlockStart = text.IndexOf("```json", StringComparison.Ordinal);
         if (codeBlockStart >= 0)
         {
@@ -118,7 +114,6 @@ public sealed class LlamaSharpCoachService(LlamaSharpAiService ai) : ICoachServi
             }
         }
 
-        // 2. Look specifically for {"kind" — the expected first field of CoachPlanDto
         var kindMarker = text.IndexOf("{\"kind\"", StringComparison.Ordinal);
         if (kindMarker < 0)
             kindMarker = text.IndexOf("{ \"kind\"", StringComparison.Ordinal);
@@ -133,7 +128,6 @@ public sealed class LlamaSharpCoachService(LlamaSharpAiService ai) : ICoachServi
             }
         }
 
-        // 3. Fallback: try each { position until one parses as valid JSON
         var searchFrom = 0;
         var globalLastBrace = text.LastIndexOf('}');
         while (searchFrom < text.Length && globalLastBrace > searchFrom)
@@ -149,9 +143,67 @@ public sealed class LlamaSharpCoachService(LlamaSharpAiService ai) : ICoachServi
             searchFrom = bracePos + 1;
         }
 
+        var firstBrace = text.IndexOf('{');
+        if (firstBrace >= 0)
+        {
+            var repaired = TryRepairJson(text[firstBrace..]);
+            if (repaired is not null)
+                return repaired;
+        }
+
         return null;
     }
 
+    private static string? TryRepairJson(string text)
+    {
+        var trimmed = text.TrimEnd();
+        var lastUseful = trimmed.Length - 1;
+        while (lastUseful >= 0)
+        {
+            var ch = trimmed[lastUseful];
+            if (ch is '}' or ']' or '"' or ',' or ':' or '{' or '[' || char.IsDigit(ch)
+                || ch is 't' or 'r' or 'u' or 'e' or 'f' or 'a' or 'l' or 's' or 'n')
+                break;
+            lastUseful--;
+        }
+
+        if (lastUseful < 0) return null;
+        trimmed = trimmed[..(lastUseful + 1)];
+
+        if (trimmed.EndsWith(','))
+            trimmed = trimmed[..^1];
+
+        var openBraces = 0;
+        var openBrackets = 0;
+        var inString = false;
+        var escape = false;
+
+        foreach (var ch in trimmed)
+        {
+            if (escape) { escape = false; continue; }
+            if (ch == '\\' && inString) { escape = true; continue; }
+            if (ch == '"') { inString = !inString; continue; }
+            if (inString) continue;
+
+            switch (ch)
+            {
+                case '{': openBraces++; break;
+                case '}': openBraces--; break;
+                case '[': openBrackets++; break;
+                case ']': openBrackets--; break;
+            }
+        }
+
+        if (openBraces <= 0 && openBrackets <= 0) return null;
+
+        var sb = new StringBuilder(trimmed);
+        for (var i = 0; i < openBrackets; i++) sb.Append(']');
+        for (var i = 0; i < openBraces; i++) sb.Append('}');
+
+        var repaired = sb.ToString();
+        return TryValidateJson(repaired) ? repaired : null;
+    }
+
     private static bool TryValidateJson(string json)
     {
         try
@@ -169,11 +221,7 @@ public sealed class LlamaSharpCoachService(LlamaSharpAiService ai) : ICoachServi
     {
         var assembly = Assembly.GetExecutingAssembly();
         var resourceName = assembly.GetManifestResourceNames()
-            .FirstOrDefault(n => n.EndsWith(fileName, StringComparison.OrdinalIgnoreCase));
-
-        if (resourceName is null)
-            throw new FileNotFoundException($"Embedded resource not found: {fileName}");
-
+            .FirstOrDefault(n => n.EndsWith(fileName, StringComparison.OrdinalIgnoreCase)) ?? throw new FileNotFoundException($"Embedded resource not found: {fileName}");
         using var stream = assembly.GetManifestResourceStream(resourceName)!;
         using var reader = new StreamReader(stream, Encoding.UTF8);
         return reader.ReadToEnd().Trim();

Journal.App/src/app.html

@@ -2,7 +2,7 @@
 <html lang="en">
   <head>
     <meta charset="utf-8" />
-    <link rel="icon" href="%sveltekit.assets%/favicon.png" />
+    <link rel="icon" href="%sveltekit.assets%/icon.ico" />
     <link
       rel="stylesheet"
       href="https://fonts.googleapis.com/css2?family=Material+Symbols+Outlined:opsz,wght,FILL,GRAD@20..48,100..700,0..1,-50..200"

Journal.App/src/lib/components/Navbar.svelte

@@ -25,7 +25,7 @@
 
 <aside class="navbar" aria-label="Primary navigation">
   <div class="navbar-header">
-    <img src="svelte.svg" alt="Journal logo" />
+    <img src="icon.png" alt="Journal logo" style="height: 48px; width: 48px;" />
   </div>
 
   <nav class="nav-groups" aria-label="Journal sections">