Add testing guide with manual verification steps

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

Author: gyaan

TESTING.md

@@ -0,0 +1,143 @@
+# Testing Guide
+
+## 1. Build & Static Analysis
+
+```bash
+go build ./...
+go vet ./...
+```
+
+## 2. Dry-Run Ingestion
+
+```bash
+go run cmd/ingest/main.go
+```
+
+Expected output:
+- 11 documents loaded
+- ~158 chunks created
+- ~1485 unique TF-IDF terms
+- 158 non-zero embeddings
+
+## 3. Start the Server
+
+```bash
+go run cmd/server/main.go
+```
+
+Expected startup logs:
+```
+Starting Customer Support RAG Server...
+Loaded 11 documents
+Created 158 chunks
+Built TF-IDF vocabulary: 1485 terms
+Indexed 158 chunks in vector store
+Server starting on port 8080
+```
+
+## 4. Health Check
+
+```bash
+curl http://localhost:8080/api/health
+```
+
+Expected:
+```json
+{"status":"healthy","active_sessions":0,"documents":158}
+```
+
+## 5. Chat Queries
+
+### Basic question (no session)
+
+```bash
+curl -s -X POST http://localhost:8080/api/chat \
+  -H "Content-Type: application/json" \
+  -d '{"query": "How do I reset my password?"}' | jq .
+```
+
+Verify: response has `session_id`, `answer`, and `sources` array.
+
+### Multi-turn conversation (reuse session)
+
+```bash
+# First message
+curl -s -X POST http://localhost:8080/api/chat \
+  -H "Content-Type: application/json" \
+  -d '{"query": "What pricing plans do you offer?"}' | jq .
+
+# Copy the session_id from the response, then:
+curl -s -X POST http://localhost:8080/api/chat \
+  -H "Content-Type: application/json" \
+  -d '{"query": "Which plan has the best value?", "session_id": "SESSION_ID_HERE"}' | jq .
+```
+
+Verify: second response references context from the first turn.
+
+### Sample queries to test different knowledge areas
+
+```bash
+# Billing
+curl -s -X POST http://localhost:8080/api/chat \
+  -H "Content-Type: application/json" \
+  -d '{"query": "Do you offer a free trial?"}' | jq .answer
+
+# Technical
+curl -s -X POST http://localhost:8080/api/chat \
+  -H "Content-Type: application/json" \
+  -d '{"query": "How do I install the chat widget on my website?"}' | jq .answer
+
+# Integrations
+curl -s -X POST http://localhost:8080/api/chat \
+  -H "Content-Type: application/json" \
+  -d '{"query": "Can I connect Salesforce to CloudSupport Pro?"}' | jq .answer
+
+# Troubleshooting
+curl -s -X POST http://localhost:8080/api/chat \
+  -H "Content-Type: application/json" \
+  -d '{"query": "The chat widget is not showing on my site"}' | jq .answer
+
+# Out-of-scope (should gracefully decline)
+curl -s -X POST http://localhost:8080/api/chat \
+  -H "Content-Type: application/json" \
+  -d '{"query": "What is the weather today?"}' | jq .answer
+```
+
+## 6. Error Cases
+
+### Empty query
+
+```bash
+curl -s -X POST http://localhost:8080/api/chat \
+  -H "Content-Type: application/json" \
+  -d '{"query": ""}' -w "\n%{http_code}"
+```
+
+Expected: `400 Bad Request`
+
+### Wrong HTTP method
+
+```bash
+curl -s -X GET http://localhost:8080/api/chat -w "\n%{http_code}"
+```
+
+Expected: `405 Method Not Allowed`
+
+### Invalid JSON
+
+```bash
+curl -s -X POST http://localhost:8080/api/chat \
+  -H "Content-Type: application/json" \
+  -d 'not json' -w "\n%{http_code}"
+```
+
+Expected: `400 Bad Request`
+
+## 7. Graceful Shutdown
+
+With the server running, press `Ctrl+C`. Expected logs:
+
+```
+Shutting down server...
+Shutdown complete
+```