feat: Complete Skill #5 - n8n Node Configuration (ALL 5 SKILLS COMPLETE!)

Implements operation-aware node configuration with progressive discovery.
Completes the final skill in the 5-skill n8n meta-skill collection.

Files created:
- 4 evaluations testing dependencies, operations, conditional fields, tool selection
- SKILL.md (692 lines) - Configuration workflow, progressive discovery, patterns
- DEPENDENCIES.md (671 lines) - displayOptions mechanism, dependency patterns
- OPERATION_PATTERNS.md (783 lines) - 20+ nodes with common configurations
- README.md (380 lines) - Skill metadata with usage statistics

Key features:
- Operation-aware configuration (resource + operation = requirements)
- Property dependencies (displayOptions show/hide rules)
- Progressive discovery (essentials → dependencies → info)
- Configuration workflow (identify → discover → configure → validate → iterate)
- 4 common node patterns (resource/operation, HTTP, database, conditional)
- Tool selection guide (get_node_essentials 91.7% success rate)
- Dependency troubleshooting (field visibility, conditional requirements)
- 20+ node configuration examples with gotchas

Progressive discovery strategy:
1. get_node_essentials (91.7% success, 18s avg from search)
2. get_property_dependencies (when dependencies unclear)
3. get_node_info (only when necessary, full schema)

Property dependency patterns:
- Boolean toggle (sendBody → body)
- Resource/operation cascade (different ops → different fields)
- Type-specific config (string vs number conditions)
- Method-specific fields (GET vs POST)

Common node patterns covered:
- HTTP Request (GET/POST/PUT/DELETE with auth, query, body)
- Webhook (basic/auth/response, $json.body gotcha)
- Slack (post/update/create channel)
- Gmail (send/get with filters)
- Postgres (query/insert/update with parameters)
- Set (fixed values/mapping with types)
- Code (per-item/all-items, no expressions!)
- IF (string/number/boolean, unary vs binary)
- Switch (rules with fallback)
- OpenAI (chat completion with system prompt)
- Schedule (daily/interval/cron with timezone)

Key insights:
- 91.7% configurations succeed with essentials only
- Average 56 seconds between configuration edits (iterative)
- 9,835 essentials calls vs fewer full schema calls
- 18 seconds average from node search to essentials
- Different operations = different requirements (always check!)

Top 5 gotchas documented:
1. Webhook data under $json.body (not $json)
2. POST needs sendBody: true
3. Slack channel format (#name for public)
4. SQL parameterized queries (prevent injection)
5. Schedule timezone must be explicit (DST handling)

displayOptions mechanism:
- show: Field appears when conditions match
- hide: Field disappears when conditions match
- AND logic: All conditions must match
- OR logic: Any value matches
- Nested: Parent value controls child structure

Total: ~2,526 lines across 8 files

Based on analysis of 38,287 workflow updates and 9,835 essentials calls.

🎉 ALL 5 CORE SKILLS NOW COMPLETE! 🎉

Skills completed:
1. ✅ n8n Expression Syntax (1,275 lines)
2. ✅ n8n MCP Tools Expert (1,325 lines)
3. ✅ n8n Workflow Patterns (3,932 lines)
4. ✅ n8n Validation Expert (2,553 lines)
5. ✅ n8n Node Configuration (2,526 lines)

Total: ~11,611 lines across 36 files + 22 evaluations
All skills data-driven from 447,557 real MCP tool usage events.

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

evaluations/node-configuration/eval-001-property-dependencies.json

@@ -0,0 +1,13 @@
+{
+  "id": "node-config-001",
+  "skills": ["n8n-node-configuration"],
+  "query": "I'm configuring an HTTP Request node with method=POST. What other fields become required or visible when I set this?",
+  "expected_behavior": [
+    "Explains property dependencies (displayOptions)",
+    "Identifies that sendBody becomes visible for POST",
+    "Explains that body becomes required when sendBody=true",
+    "Suggests using get_property_dependencies to see all dependencies",
+    "Provides guidance on checking conditional requirements",
+    "May reference DEPENDENCIES.md for detailed dependency rules"
+  ]
+}

evaluations/node-configuration/eval-002-operation-specific-config.json

@@ -0,0 +1,13 @@
+{
+  "id": "node-config-002",
+  "skills": ["n8n-node-configuration"],
+  "query": "How do I configure a Slack node to post a message? What fields are required for this specific operation?",
+  "expected_behavior": [
+    "Identifies need to set resource='message' and operation='post'",
+    "Explains operation-specific required fields (channel, text)",
+    "Suggests using get_node_essentials with operation context",
+    "Provides example configuration for this operation",
+    "May reference OPERATION_PATTERNS.md for Slack patterns",
+    "Explains that different operations have different requirements"
+  ]
+}

evaluations/node-configuration/eval-003-conditional-fields.json

@@ -0,0 +1,13 @@
+{
+  "id": "node-config-003",
+  "skills": ["n8n-node-configuration"],
+  "query": "My IF node configuration is valid with operation='equals', but when I change to operation='isEmpty', validation fails. Why?",
+  "expected_behavior": [
+    "Explains that isEmpty is a unary operator (single value)",
+    "Identifies that value2 is not needed for unary operators",
+    "Explains singleValue property dependency",
+    "Mentions auto-sanitization will fix operator structure",
+    "Suggests using get_property_dependencies to understand operator rules",
+    "May reference DEPENDENCIES.md for operator-specific dependencies"
+  ]
+}

evaluations/node-configuration/eval-004-essentials-vs-info.json

@@ -0,0 +1,13 @@
+{
+  "id": "node-config-004",
+  "skills": ["n8n-node-configuration"],
+  "query": "Should I use get_node_essentials or get_node_info when configuring a new node? What's the difference?",
+  "expected_behavior": [
+    "Recommends get_node_essentials for configuration (91.7% success rate)",
+    "Explains essentials provides required fields and options",
+    "Explains get_node_info provides full schema (use when essentials insufficient)",
+    "Suggests starting with essentials, escalate to info if needed",
+    "May provide telemetry insight (essentials used 9,835 times)",
+    "References progressive disclosure approach"
+  ]
+}