Remove Needle; stop paging on nginx 4xx

Needle scored ~chance on the golden set and never gated alerts, so drop the
sidecar, proxy handlers, UI buttons, k8s container and build step. The labelled
eval sets move to cmd/triage-eval/data.

nginx 4xx (registry 401 challenges, /oauth2/auth, scanner 405s) is now dropped
in FilterActionable instead of only being discounted, so it cannot ride along
with a real 5xx. nginx 5xx still alerts.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

k8s/deployment.yaml

@@ -173,8 +173,6 @@ spec:
           value: "15m"
         - name: OTEL_HONEYPOT_TTL
           value: "1h"
-        - name: OTEL_NEEDLE_ADDR
-          value: "http://127.0.0.1:5005"
         # ~80% of the memory limit so the GC works harder before an OOMKill.
         - name: GOMEMLIMIT
           value: "800MiB"
@@ -202,40 +200,6 @@ spec:
           limits:
             memory: "1Gi"
             cpu: "500m"
-      - name: needle-sidecar
-        image: matst80/needle-sidecar:latest
-        imagePullPolicy: Always
-        ports:
-        - containerPort: 5005
-          name: needle-http
-        env:
-        - name: HOME
-          value: "/app"
-        - name: NEEDLE_PORT
-          value: "5005"
-        - name: NEEDLE_HOST
-          value: "0.0.0.0"
-        - name: NEEDLE_TELEMETRY
-          value: "0"
-        livenessProbe:
-          httpGet:
-            path: /health
-            port: needle-http
-          initialDelaySeconds: 5
-          periodSeconds: 15
-        readinessProbe:
-          httpGet:
-            path: /health
-            port: needle-http
-          initialDelaySeconds: 3
-          periodSeconds: 10
-        resources:
-          requests:
-            memory: "512Mi"
-            cpu: "200m"
-          limits:
-            memory: "2Gi"
-            cpu: "4000m"
       volumes:
       - name: log-dir
         emptyDir: {}