feat: 16.0 - Frontend - Delete habit with confirmation

progress.txt

@@ -578,3 +578,41 @@ NEXT STEPS:
     Files modified:
     - dashboard/habits.html (enhanced mobile CSS, added input attributes)
     - dashboard/test_habits_mobile.py (created)
+
+[✓] Story 15.0: Backend - Delete habit endpoint
+    Commit: 0f9c0de
+    Date: 2026-02-10
+    
+    Implementation:
+    - Added do_DELETE method to api.py for handling DELETE requests
+    - Route: DELETE /api/habits/{id} deletes habit by ID
+    - Extracts habit ID from URL path (/api/habits/{id})
+    - Returns 404 if habit not found in habits.json
+    - Removes habit from habits array using list.pop(index)
+    - Updates lastUpdated timestamp after deletion
+    - Returns 200 with success message, including deleted habit ID
+    - Graceful error handling for missing/corrupt habits.json (returns 404)
+    - Follows existing API patterns (similar to handle_habits_check)
+    - Error responses include descriptive error messages
+    
+    Tests:
+    - Created dashboard/test_habits_delete.py with 6 comprehensive tests
+    - Tests for habit removal from habits.json file (AC1)
+    - Tests for 200 status with success message response (AC2)
+    - Tests for 404 when habit not found (AC3)
+    - Tests for lastUpdated timestamp update (AC4)
+    - Tests for edge cases: deleting already deleted habit, invalid paths
+    - Tests for graceful handling when habits.json is missing
+    - All 6 tests pass ✓ (AC5)
+    - All previous tests (schema, GET, POST, streak, check) still pass ✓
+    
+    Files modified:
+    - dashboard/api.py (added do_DELETE method and handle_habits_delete)
+    - dashboard/test_habits_delete.py (created)
+
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+NEXT STEPS:
+- Continue with remaining 2 stories (16.0, 17.0)
+
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