feat(#39): Add a Statistics tab to the ledger view

docs/mammon-api.yml

@@ -904,6 +904,34 @@ paths:
                   $ref: "#/components/schemas/TransactionResponse"
         "404":
           description: No ledger with this id
+  /ledgers/{ledgerId}/profit:
+    get:
+      tags:
+      - transaction
+      summary: Get the daily profit series for a single ledger
+      operationId: profitPerDayInLedger
+      parameters:
+      - name: ledgerId
+        in: path
+        description: Id of the ledger
+        required: true
+        schema:
+          type: string
+          format: uuid
+      responses:
+        "200":
+          description: "Daily profit for the ledger, ascending by date, only for days\
+            \ with ISK activity"
+          content:
+            '*/*':
+              schema:
+                type: array
+                items:
+                  $ref: "#/components/schemas/DailyProfitResponse"
+        "400":
+          description: The ledger is the system ledger or a combined ledger
+        "404":
+          description: No ledger with this id
   /ledgers/{ledgerId}/balance:
     get:
       tags:
@@ -1682,7 +1710,7 @@ components:
           type: string
           format: date-time
           description: When the order was issued.
-          example: 2026-06-22T05:12:25Z
+          example: 2026-06-22T05:12:25
         escrow:
           type: number
           description: ISK held in escrow for a buy order; null for sell orders.
@@ -1910,6 +1938,32 @@ components:
           type: string
       required:
       - type
+    DailyProfitResponse:
+      type: object
+      description: "Profit for a single day: ISK in, ISK out, and their difference."
+      properties:
+        date:
+          type: string
+          format: date
+          description: The UTC (EVE) day this profit is for.
+          example: 2026-06-22
+        iskIn:
+          type: number
+          description: Total ISK that entered the ledger on this day.
+          example: 1500000.0
+        iskOut:
+          type: number
+          description: Total ISK that left the ledger on this day.
+          example: 500000.0
+        profit:
+          type: number
+          description: "Profit for the day: iskIn minus iskOut."
+          example: 1000000.0
+      required:
+      - date
+      - iskIn
+      - iskOut
+      - profit
     BalanceResponse:
       type: object
       description: "The balance of a ledger: its ISK total plus the quantity of each\