feat(network): SSE optimization for local LLM streaming (#31 #32 #33) (#26)

Addresses three critical network issues for LLM streaming performance:

**#33 Disable proxy buffering for SSE**
- Add X-Accel-Buffering: no header to response
- Tells nginx/Ingress to stream events immediately instead of buffering

**#32 HTTP/2 multiplexing for concurrent streams**
- Enable HTTP/2 in server config via http2.ConfigureServer()
- Increase MaxConnsPerHost to 10 for better concurrency
- Allows multiple concurrent LLM requests without blocking

**#31 TCP backpressure for streaming LLM responses**
- Set TCP_NODELAY on dialer to disable Nagle's algorithm
- Reduces latency by sending small packets immediately
- Critical for low TTFT (time-to-first-token) under load

**Tests added:**
- TestTCPBackpressure: Verifies TCP backpressure handling with slow client
- TestConcurrentSSEStreams: Confirms HTTP/2 multiplexing works correctly

---------

Co-authored-by: poison <[email protected]>
Reviewed-on: #26
Co-authored-by: poimen <[email protected]>

k8s/tekton/kustomization.yaml

@@ -6,6 +6,9 @@ namespace: api
 resources:
 - ci-rbac.yaml
 - task-integration-test.yaml
+- task-load-test.yaml
+- task-workflow-visibility.yaml
+- pipeline-sse-optimization.yaml
 
 generatorOptions:
   disableNameSuffixHash: true
@@ -14,3 +17,9 @@ configMapGenerator:
 - name: integration-test-script
   files:
   - scripts/integration-test.sh
+- name: load-test-script
+  files:
+  - scripts/load-test.sh
+- name: workflow-visibility-test-script
+  files:
+  - scripts/workflow-visibility-test.sh