chore: update n8n to 2.8.3 (#603)

* chore: update n8n to 2.8.3 and bump version to 2.35.3

- Updated n8n from 2.6.3 to 2.8.3
- Updated n8n-core from 2.6.1 to 2.8.1
- Updated n8n-workflow from 2.6.0 to 2.8.0
- Updated @n8n/n8n-nodes-langchain from 2.6.2 to 2.8.1
- Fixed node loader to bypass restricted package.json exports in
  @n8n/n8n-nodes-langchain >=2.9.0 (resolves via absolute paths)
- Fixed community doc generator for cloud LLMs: added API key env var
  support, switched to max_completion_tokens, auto-omit temperature
- Rebuilt node database with 1,236 nodes (673 n8n-nodes-base,
  133 @n8n/n8n-nodes-langchain, 430 community)
- Refreshed community nodes (361 verified + 69 npm) with 424 AI summaries
- Updated README badge with new n8n version and node counts
- Updated CHANGELOG with dependency changes

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: update documentation-generator tests for max_completion_tokens

- Updated test assertions from max_tokens to max_completion_tokens
- Updated testConnection token limit expectation from 10 to 200
- Added temperature to test config to match new configurable behavior

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

tests/unit/community/documentation-generator.test.ts

@@ -41,6 +41,7 @@ describe('DocumentationGenerator', () => {
     apiKey: 'test-key',
     timeout: 30000,
     maxTokens: 1000,
+    temperature: 0.3,
   };
 
   const validSummary = {
@@ -163,7 +164,7 @@ describe('DocumentationGenerator', () => {
 
         expect(mockCreate).toHaveBeenCalledWith({
           model: 'test-model',
-          max_tokens: 1000,
+          max_completion_tokens: 1000,
           temperature: 0.3,
           messages: expect.arrayContaining([
             expect.objectContaining({ role: 'system' }),
@@ -680,7 +681,7 @@ describe('DocumentationGenerator', () => {
 
       expect(mockCreate).toHaveBeenCalledWith(
         expect.objectContaining({
-          max_tokens: 10,
+          max_completion_tokens: 200,
           messages: [
             {
               role: 'user',