refactor(api): centralize API key management

[41tair]

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Summary

part of #39993

Screenshots

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Checklist

• This change requires a documentation update, included: Dify Document
• I understand that this PR may be closed in case there was no previous discussion or issues. (This doesn't apply to typos!)
• I've verified the change and added or updated tests where meaningful regression risk justifies coverage.
• I've updated the documentation accordingly.
• I ran make lint && make type-check (backend) and vp staged (frontend) to appease the lint gods

[github-actions]

Pyrefly Diff

base → PR

--- /tmp/pyrefly_base.txt	2026-09-18 06:09:45.447703396 +0000
+++ /tmp/pyrefly_pr.txt	2026-09-18 06:09:37.147660365 +0000
@@ -1809,29 +1809,29 @@
 ERROR No attribute `MethodView` in module `builtins` [missing-attribute]
  --> tests/unit_tests/controllers/common/test_fields.py:8:5
 ERROR `in` is not supported between `Literal['Incorrect API key provided']` and `None` [not-iterable]
-    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:1748:12
+    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:1684:12
 ERROR `in` is not supported between `Literal['Start a new conversation']` and `None` [not-iterable]
-    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:1780:12
+    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:1716:12
 ERROR Argument `test_drain_streaming_generate_response_returns_on_message_end.ClosableResponse` is not assignable to parameter `response` with type `Generator[str] | RateLimitGenerator` in function `controllers.console.app.completion._drain_streaming_generate_response` [bad-argument-type]
-    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:1903:69
+    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:1839:69
 ERROR Argument `Iterator[str]` is not assignable to parameter `response` with type `Generator[str] | RateLimitGenerator` in function `controllers.console.app.completion._drain_streaming_generate_response` [bad-argument-type]
-    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:1910:66
+    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:1846:66
 ERROR Argument `Iterator[str]` is not assignable to parameter `response` with type `Generator[str] | RateLimitGenerator` in function `controllers.console.app.completion._drain_streaming_generate_response` [bad-argument-type]
-    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:1916:66
+    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:1852:66
 ERROR Object of class `object` has no attribute `data` [missing-attribute]
-    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:2338:50
+    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:2274:50
 ERROR Object of class `object` has no attribute `limit` [missing-attribute]
-    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:2339:30
+    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:2275:30
 ERROR Object of class `object` has no attribute `has_more` [missing-attribute]
-    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:2340:33
+    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:2276:33
 ERROR Object of class `object` has no attribute `data` [missing-attribute]
-    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:2383:50
+    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:2319:50
 ERROR Object of class `object` has no attribute `limit` [missing-attribute]
-    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:2384:30
+    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:2320:30
 ERROR Object of class `object` has no attribute `has_more` [missing-attribute]
-    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:2385:33
+    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:2321:33
 ERROR Argument `Literal['00000000-0000-0000-0000-000000000002']` is not assignable to parameter `message_id` with type `UUID` in function `controllers.console.app.message._get_message_suggested_questions` [bad-argument-type]
-    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:2487:24
+    --> tests/unit_tests/controllers/console/agent/test_agent_controllers.py:2423:24
 ERROR Object of class `int` has no attribute `lower` [missing-attribute]
    --> tests/unit_tests/controllers/console/app/test_annotation_security.py:237:38
 ERROR Object of class `int` has no attribute `lower` [missing-attribute]
@@ -1925,9 +1925,7 @@
 ERROR Argument `scoped_session[flask_sqlalchemy.session.Session]` is not assignable to parameter `session` with type `sqlalchemy.orm.session.Session` in function `_add_binding` [bad-argument-type]
   --> tests/unit_tests/controllers/console/datasets/test_data_source.py:85:28
 ERROR Missing argument `name` in function `controllers.console.datasets.datasets.DatasetCreatePayload.__init__` [missing-argument]
-   --> tests/unit_tests/controllers/console/datasets/test_datasets.py:602:49
-ERROR Object of class `NoneType` has no attribute `token` [missing-attribute]
-    --> tests/unit_tests/controllers/console/datasets/test_datasets.py:1528:16
+   --> tests/unit_tests/controllers/console/datasets/test_datasets.py:605:49
 ERROR Argument `Literal['custom']` is not assignable to parameter `mode` with type `ProcessRuleMode | SQLCoreOperations[ProcessRuleMode]` in function `models.dataset.DatasetProcessRule.__init__` [bad-argument-type]
    --> tests/unit_tests/controllers/console/datasets/test_datasets_document.py:246:18
 ERROR Argument `Literal['custom']` is not assignable to parameter `mode` with type `ProcessRuleMode | SQLCoreOperations[ProcessRuleMode]` in function `models.dataset.DatasetProcessRule.__init__` [bad-argument-type]

[github-actions]

Pyrefly Type Coverage

Metric	Base	PR	Delta
Type coverage	64.47%	64.59%	+0.13%
Strict coverage	64.07%	64.20%	+0.13%
Typed symbols	46,688	46,957	+269
Untyped symbols	25,893	25,896	+3
Modules	3419	3441	+22

[codecov]

Codecov Report

❌ Patch coverage is 99.09502% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 87.48%. Comparing base (6024141) to head (aed2b05).
⚠️ Report is 11 commits behind head on main.

Files with missing lines	Patch %	Lines
api/fields/api_key_fields.py	87.09%	2 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #42489      +/-   ##
==========================================
+ Coverage   87.40%   87.48%   +0.08%     
==========================================
  Files        5463     5477      +14     
  Lines      315623   316985    +1362     
  Branches    63604    63514      -90     
==========================================
+ Hits       275863   277316    +1453     
+ Misses      34377    34287      -90     
+ Partials     5383     5382       -1     

Flag	Coverage Δ
api	87.10% <99.09%> (+0.01%)	⬆️
dify-ui	93.14% <ø> (-0.60%)	⬇️
web	87.94% <ø> (+0.16%)	⬆️

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