Fix DetectIntent ordering bug and substring matching in parse hints

- Reorder DetectIntent checks so "unarchive" is checked before "archive"
  (previously "unarchive" was always misclassified as "archive" because
  the string contains the substring)
- Switch from substring matching to whole-word matching in both
  DetectIntent and FindClosestPattern to prevent false positives
  (e.g. "sunset" matching "set", "address" matching "add")
- Use lastIndexOf for PARSE_HINT marker in frontend to handle edge case
  where LLM response contains the marker text
- Add regression tests for "unarchive my board" and "rename board"

Author: Chris0Jeky

backend/src/Taskdeck.Application/Services/AutomationPlannerService.cs

@@ -461,19 +461,25 @@ internal static string BuildParseHintMessage(string instruction)
     internal static string? DetectIntent(string instruction)
     {
         var lower = instruction.Trim().ToLowerInvariant();
+        var words = lower.Split(' ', StringSplitOptions.RemoveEmptyEntries);
+
+        // Check more-specific intents before their substrings (e.g. "unarchive" before "archive",
+        // "rename" before "new"). Use word-level matching to avoid substring false positives
+        // like "sunset" matching "set" or "address" matching "add".
+        bool hasWord(string word) => words.Any(w => w == word);
 
-        if (lower.Contains("create") || lower.Contains("add") || lower.Contains("new"))
+        if (lower.Contains("unarchive") || hasWord("restore"))
+            return "unarchive";
+        if (lower.Contains("rename") || hasWord("edit") || hasWord("change") || hasWord("update"))
+            return "update";
+        if (hasWord("reorder") || hasWord("position"))
+            return "reorder";
+        if (hasWord("create") || hasWord("add") || hasWord("new"))
             return "create";
-        if (lower.Contains("move") || lower.Contains("drag") || lower.Contains("transfer"))
+        if (hasWord("move") || hasWord("drag") || hasWord("transfer"))
             return "move";
-        if (lower.Contains("archive") || lower.Contains("remove") || lower.Contains("delete"))
+        if (hasWord("archive") || hasWord("remove") || hasWord("delete"))
             return "archive";
-        if (lower.Contains("update") || lower.Contains("edit") || lower.Contains("change") || lower.Contains("rename") || lower.Contains("set"))
-            return "update";
-        if (lower.Contains("unarchive") || lower.Contains("restore"))
-            return "unarchive";
-        if (lower.Contains("reorder") || lower.Contains("position"))
-            return "reorder";
 
         return null;
     }
@@ -490,10 +496,10 @@ internal static (string Pattern, string Example) FindClosestPattern(string instr
         {
             var score = 0;
 
-            // Boost patterns whose keywords overlap with the instruction words
+            // Boost patterns whose keywords match whole words in the instruction
             foreach (var keyword in entry.Keywords)
             {
-                if (words.Any(w => w.Contains(keyword)))
+                if (words.Any(w => w == keyword))
                     score += 2;
             }
 

backend/tests/Taskdeck.Application.Tests/Services/AutomationPlannerServiceTests.cs

@@ -860,6 +860,8 @@ public async Task ParseInstruction_ShouldReturnStructuredParseHint_ForUnrecogniz
     [InlineData("delete old stuff", "archive")]
     [InlineData("change the card name", "update")]
     [InlineData("restore the board", "unarchive")]
+    [InlineData("unarchive my board", "unarchive")]
+    [InlineData("rename board to Sprint 5", "update")]
     public void DetectIntent_ShouldIdentifyIntent_FromNaturalLanguage(string instruction, string expectedIntent)
     {
         // Act

frontend/taskdeck-web/src/utils/chat.ts

@@ -20,7 +20,7 @@ export interface ParsedHintMessage {
 }
 
 export function extractParseHint(content: string): ParsedHintMessage | null {
-  const markerIndex = content.indexOf(PARSE_HINT_MARKER)
+  const markerIndex = content.lastIndexOf(PARSE_HINT_MARKER)
   if (markerIndex === -1) {
     return null
   }