feat(budget): tx edit --budget and budget update (v0.5.0)HEADv0.5.0master

Add two deferred budget follow-ups:
- tx edit --budget: re-assign a budget on an existing transaction,
  mirroring the existing tx add --budget flag (name/id resolved, hard
  error on miss). Resolves the ISSUES.md backfill wish.
- budget update: rename a budget and/or edit its auto-budget fields via
  PUT /budgets/{id}; only fields passed are sent, empty is a hard error.

New command adds to the CLI surface without breaking callers, so this is
a MINOR bump (0.4.1 -> 0.5.0). Docs (README, SKILL.md), completion, and
TODO synced. The tx add --budget-id item stays open (still YAGNI).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

2 files changed, 60 insertions, 4 deletions

diff --git a/tests/unit/test_commands_budget.py b/tests/unit/test_commands_budget.py
index b365d27..96452c1 100644
--- a/tests/unit/test_commands_budget.py
+++ b/tests/unit/test_commands_budget.py
@@ -119,6 +119,47 @@ class TestBudgetLifecycle(unittest.TestCase):
         self.assertFalse(client.request.call_args[1]["body"]["active"])
 
 
+class TestBudgetUpdate(unittest.TestCase):
+    def _resolver(self):
+        r = MagicMock()
+        r.budget.return_value = {"id": "5", "name": "Rent"}
+        return r
+
+    def _args(self, **kw):
+        base = dict(ref="Rent", name=None, currency=None, auto_budget_amount=None,
+                    auto_budget_period=None, auto_budget_type=None)
+        base.update(kw)
+        return SimpleNamespace(**base)
+
+    def test_rename_puts_name(self):
+        client = MagicMock()
+        client.request.return_value = {"data": {"id": "5", "attributes": {}}}
+        budget.cmd_update(self._args(name="Housing"),
+                          _ctx(client=client, resolver=self._resolver()))
+        method, path = client.request.call_args[0][:2]
+        body = client.request.call_args[1]["body"]
+        self.assertEqual((method, path), ("PUT", "/api/v1/budgets/5"))
+        self.assertEqual(body, {"name": "Housing"})
+
+    def test_auto_budget_fields(self):
+        client = MagicMock()
+        client.request.return_value = {"data": {"id": "5", "attributes": {}}}
+        budget.cmd_update(
+            self._args(auto_budget_amount=500, auto_budget_period="monthly",
+                       auto_budget_type="reset", currency="EUR"),
+            _ctx(client=client, resolver=self._resolver()))
+        body = client.request.call_args[1]["body"]
+        self.assertEqual(body["auto_budget_amount"], "500")
+        self.assertEqual(body["auto_budget_period"], "monthly")
+        self.assertEqual(body["auto_budget_type"], "reset")
+        self.assertEqual(body["currency_code"], "EUR")
+        self.assertNotIn("name", body)
+
+    def test_no_fields_errors(self):
+        with self.assertRaises(FireflyError):
+            budget.cmd_update(self._args(), _ctx(resolver=self._resolver()))
+
+
 class TestBudgetLimit(unittest.TestCase):
     def _resolver(self):
         r = MagicMock()
@@ -168,6 +209,7 @@ class TestBudgetRegistration(unittest.TestCase):
         expected = {
             "budget list": budget.cmd_list,
             "budget create": budget.cmd_create,
+            "budget update": budget.cmd_update,
             "budget delete": budget.cmd_delete,
             "budget enable": budget.cmd_enable,
             "budget disable": budget.cmd_disable,
diff --git a/tests/unit/test_commands_transaction.py b/tests/unit/test_commands_transaction.py
index 7366b5c..ec4e54c 100644
--- a/tests/unit/test_commands_transaction.py
+++ b/tests/unit/test_commands_transaction.py
@@ -274,7 +274,8 @@ class TestTxEdit(unittest.TestCase):
         ctx, client, resolver = make_ctx()
         client.request.return_value = {"data": {"id": "9", "attributes": {}}}
         args = MagicMock(id="9", amount="12.00", date=None, desc="fixed",
-                         source=None, dest=None, category=None, tags=None, type=None)
+                         source=None, dest=None, category=None, tags=None,
+                         budget=None, type=None)
         rc = tx.cmd_edit(args, ctx)
         self.assertEqual(rc, 0)
         method, path = client.request.call_args[0][:2]
@@ -291,7 +292,8 @@ class TestTxEdit(unittest.TestCase):
         }[n]
         client.request.return_value = {"data": {"id": "9", "attributes": {}}}
         args = MagicMock(id="9", amount=None, date=None, desc=None,
-                         source="BBVA", dest="Medio", category=None, tags=None, type=None)
+                         source="BBVA", dest="Medio", category=None, tags=None,
+                         budget=None, type=None)
         tx.cmd_edit(args, ctx)
         split = client.request.call_args[1]["body"]["transactions"][0]
         self.assertEqual(split, {"source_id": "3", "destination_id": "4"})
@@ -300,7 +302,8 @@ class TestTxEdit(unittest.TestCase):
         ctx, client, resolver = make_ctx()
         client.request.return_value = {"data": {"id": "9", "attributes": {}}}
         args = MagicMock(id="9", amount=None, date=None, desc=None, source=None,
-                         dest=None, category="Cat", tags="a, b", type="transfer")
+                         dest=None, category="Cat", tags="a, b", budget=None,
+                         type="transfer")
         tx.cmd_edit(args, ctx)
         split = client.request.call_args[1]["body"]["transactions"][0]
         self.assertEqual(split,
@@ -311,11 +314,22 @@ class TestTxEdit(unittest.TestCase):
         from firefly_cli.errors import FireflyError
         ctx, client, _ = make_ctx()
         args = MagicMock(id="9", amount=None, date=None, desc=None, source=None,
-                         dest=None, category=None, tags=None, type=None)
+                         dest=None, category=None, tags=None, budget=None, type=None)
         with self.assertRaises(FireflyError):
             tx.cmd_edit(args, ctx)
         client.request.assert_not_called()
 
+    def test_edit_budget_ref_sets_budget_id(self):
+        ctx, client, resolver = make_ctx()
+        resolver.budget.return_value = {"id": "12", "name": "Groceries"}
+        client.request.return_value = {"data": {"id": "9", "attributes": {}}}
+        args = MagicMock(id="9", amount=None, date=None, desc=None, source=None,
+                         dest=None, category=None, tags=None, budget="Groceries",
+                         type=None)
+        tx.cmd_edit(args, ctx)
+        split = client.request.call_args[1]["body"]["transactions"][0]
+        self.assertEqual(split, {"budget_id": "12"})
+
 
 class TestTxDelete(unittest.TestCase):
     def test_delete_requires_yes(self):