feat: knowledge pipeline (#25360)

Signed-off-by: -LAN- <laipz8200@outlook.com>
Co-authored-by: twwu <twwu@dify.ai>
Co-authored-by: crazywoola <100913391+crazywoola@users.noreply.github.com>
Co-authored-by: jyong <718720800@qq.com>
Co-authored-by: Wu Tianwei <30284043+WTW0313@users.noreply.github.com>
Co-authored-by: QuantumGhost <obelisk.reg+git@gmail.com>
Co-authored-by: lyzno1 <yuanyouhuilyz@gmail.com>
Co-authored-by: quicksand <quicksandzn@gmail.com>
Co-authored-by: Jyong <76649700+JohnJyong@users.noreply.github.com>
Co-authored-by: lyzno1 <92089059+lyzno1@users.noreply.github.com>
Co-authored-by: zxhlyh <jasonapring2015@outlook.com>
Co-authored-by: Yongtao Huang <yongtaoh2022@gmail.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Joel <iamjoel007@gmail.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: nite-knite <nkCoding@gmail.com>
Co-authored-by: Hanqing Zhao <sherry9277@gmail.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Co-authored-by: Harry <xh001x@hotmail.com>

api/tests/fixtures/workflow/basic_chatflow.yml

@@ -0,0 +1,102 @@
+app:
+  description: Simple chatflow contains only 1 LLM node.
+  icon: 🤖
+  icon_background: '#FFEAD5'
+  mode: advanced-chat
+  name: basic_chatflow
+  use_icon_as_answer_icon: false
+dependencies: []
+kind: app
+version: 0.3.1
+workflow:
+  conversation_variables: []
+  environment_variables: []
+  features:
+    file_upload: {}
+    opening_statement: ''
+    retriever_resource:
+      enabled: true
+    sensitive_word_avoidance:
+      enabled: false
+    speech_to_text:
+      enabled: false
+    suggested_questions: []
+    suggested_questions_after_answer:
+      enabled: false
+    text_to_speech:
+      enabled: false
+      language: ''
+      voice: ''
+  graph:
+    edges:
+    - id: 1755189262236-llm
+      source: '1755189262236'
+      sourceHandle: source
+      target: llm
+      targetHandle: target
+    - id: llm-answer
+      source: llm
+      sourceHandle: source
+      target: answer
+      targetHandle: target
+    nodes:
+    - data:
+        desc: ''
+        title: Start
+        type: start
+        variables: []
+      id: '1755189262236'
+      position:
+        x: 80
+        y: 282
+      sourcePosition: right
+      targetPosition: left
+      type: custom
+    - data:
+        context:
+          enabled: false
+          variable_selector: []
+        desc: ''
+        memory:
+          query_prompt_template: '{{#sys.query#}}
+
+
+            {{#sys.files#}}'
+          window:
+            enabled: false
+            size: 10
+        model:
+          completion_params:
+            temperature: 0.7
+          mode: chat
+          name: ''
+          provider: ''
+        prompt_template:
+        - role: system
+          text: ''
+        selected: true
+        title: LLM
+        type: llm
+        variables: []
+        vision:
+          enabled: false
+      id: llm
+      position:
+        x: 380
+        y: 282
+      sourcePosition: right
+      targetPosition: left
+      type: custom
+    - data:
+        answer: '{{#llm.text#}}'
+        desc: ''
+        title: Answer
+        type: answer
+        variables: []
+      id: answer
+      position:
+        x: 680
+        y: 282
+      sourcePosition: right
+      targetPosition: left
+      type: custom