feat: allow editing frequency and target_value on habits

- Add frequency to UpdateHabitRequest (was immutable, now editable)
- Validate frequency + specific_days/dates coherence on update
- Keep type and is_negative immutable (they change entry semantics)
- Remove completion_rate references from swagger and README

docs/docs.go

@@ -1172,7 +1172,7 @@ const docTemplate = `{
                         "BearerAuth": []
                     }
                 ],
-                "description": "Get statistics for a specific habit including streaks and completion rates",
+                "description": "Get statistics for a specific habit including streaks and completions",
                 "produces": [
                     "application/json"
                 ],
@@ -1800,6 +1800,9 @@ const docTemplate = `{
                 "description": {
                     "type": "string"
                 },
+                "frequency": {
+                    "$ref": "#/definitions/value_objects.Frequency"
+                },
                 "name": {
                     "type": "string"
                 },

docs/swagger.json

@@ -1164,7 +1164,7 @@
                         "BearerAuth": []
                     }
                 ],
-                "description": "Get statistics for a specific habit including streaks and completion rates",
+                "description": "Get statistics for a specific habit including streaks and completions",
                 "produces": [
                     "application/json"
                 ],
@@ -1792,6 +1792,9 @@
                 "description": {
                     "type": "string"
                 },
+                "frequency": {
+                    "$ref": "#/definitions/value_objects.Frequency"
+                },
                 "name": {
                     "type": "string"
                 },

docs/swagger.yaml

@@ -268,6 +268,8 @@ definitions:
         type: boolean
       description:
         type: string
+      frequency:
+        $ref: '#/definitions/value_objects.Frequency'
       name:
         type: string
       specific_dates:
@@ -1189,8 +1191,7 @@ paths:
       - system
   /stats/habits/{id}:
     get:
-      description: Get statistics for a specific habit including streaks and completion
-        rates
+      description: Get statistics for a specific habit including streaks and completions
       parameters:
       - description: Habit ID
         in: path